The film starts in 1693 in Salem, Massachusetts, with teenager Thackery Binx being awoken by a woman passing his window and then comes to realise that his younger sister, Emily, is missing. After investigating outside he sees Emily heading towards the nearby woods and after chasing her, Binx comes across a cottage. He secretly enters the building to find his sister being surrounded by three witch sisters, Winifred, Sarah, and Mary Sanderson. However, he has arrived too late to find that the sisters have sucked the life force out of the young girl, resulting in the once old women becoming younger again. Losing in a scuffle with the three witches, Thackery is turned into a black cat doomed to live forever with the guilt of not being able to save his sister, which amuses the witches. Their games end suddenly with the local townspeople, led by Binx's parents, apprehending the three women and hanging them for their crimes. Before they die however, Winnie warns the people that they will return on a Halloween night after being awoken from death by a virgin.



Fast forward to Halloween 1993, exactly 300 years later. Max Dennison is a teenager who has been forced to move away with his family from his beloved hometown of Los Angeles, California to Salem. Having just heard the story of the witches, a story that everyone in the town knows and loves, he shows he is less than impressed with it and the holiday itself. His younger sister, Dani, on the other hand, isn't having nearly as hard a time coping as her brother and is getting ready for a night of trick or treating.



After much protesting, Dani eventually gets her way and convinces Max to take her trick or treating as they used to do. Along the way, they happen upon the house of Allison, Max's crush from school. Allison brings up the Sanderson sisters again, which interests Dani. They all three decide to leave her parents' Halloween party so they can explore the abandoned Sanderson sister's cottage which has since been turned into a museum. When inside, Max hears the story of the Black Flamed Candle by Allison (the candle when lit will bring the witches back) and laughs at what he believes to be myth. He lights the candle and the room bursts into life with all the bulbs bursting and returning to flamed lighting. The events end with the three sisters arriving back, rejoicing that Winnie's curse worked. Mary reveals that she can smell Dani to her sisters, and all three find the girl and surround her. They are interrupted by Max who tricks the three into believing he himself has magic by producing fire from his hand (lighting the lighter) and producing water (the fire safety system). The boy then steals Winnie's spell book (which has an eye on the cover) after being made too by Binx, the black cat.



The group are led to a graveyard and Thackery recounts the story of the witches and his sister. The three sisters however have since realised that they were tricked and fly after them. It is revealed that the witches can't touch the ground in the graveyard because it is hallowed ground. Therefore, Winnie resurrects an old lover, Billie, and orders him to chase after them. The group escape by running through the sewers and witness Binx getting run over by a bus (which is being driven by Sarah) and coming back to life again.



The witches chase the group to a variety of places, such as the town dance, which sees the sisters sing a spell to the guests which causes them to dance until they die. They are then led to Max's school which sees them get led into a trap within a kiln and apparently burned alive. The kids leave and return to Max's house whilst the witches return to life and their own home as Winnie comes to the conclusion that they're going to die because she can't remember the potion to produce life force for them to suck out of children. However, the kids open her book which immediately alerts the witches to their position. Having lost their brooms previously they are resorted to using a large brush, a mop and a hoover to use as flying objects. They break into Max's home, and gain hold of the book and Dani, who they will use to produce life force. It is revealed by Winnie that the candle is almost out and dawn approaches, signifying that they will die if they don't receive life force in time of sunrise.



For the final time, Max tricks the witches back at their cottage by pretending the headlights on his car is actually the sun, and takes back his sister. The witches give chase and end up back at the graveyard which sees Billy switch sides to help against Winnie. Dani is protected but runs off to catch Billy's head when it is knocked off by Winnie. This causes the main witch to swoop down and take Dani. Whilst hovering, Binx jumps and attacks the witch who drops a vial of potion of which Max catches and drinks for himself and throws the cat against a rock. Angered, Winnie drops Dani and lifts up Max and starts draining his life force. She loses concentration when Mary and Sarah fly past her, allowing Max to attack and they both fall to the ground. Winnie crawls over to him and begins sucking out his life-force but because she is standing on hallowed ground, she turns to stone and then all three witches explode with the sun beginning to rise.



After realising the curse has lifted and Binx is dead, the trio are greeted by his ghost form who finally meets his dead sister and the pair walk off together.



The film ends with the eye of the spell book opening up, questioning or not the theory that the three Sanderson witches are actually dead.