The museum is hosting events from October 21 to 31 and youngsters have turned up in their scariest costumes to claim a trick or treat prize.
Activities taking place until October 31 include a Halloween Trail from 10am-5pm costing £2 per person and creepy crafts each day between 10am and midday, costing £2 per person. There will also be the chance to explore its Haunted Galleries from 10am-5pm which is free and a Halloween Disco Daily from 1pm-4pm which is also free.
Here are 9 images from the spooky fun so far this week:
1. Dress to Distress at Portsmouth Museum
Dress to Distress at Portsmouth Museum. Photos by Matthew Clark Photo: Matthew Clark
2. Dress to Distress at Portsmouth Museum
Dress to Distress at Portsmouth Museum.
Photos by Matthew Clark Photo: Matthew Clark
3. Dress to Distress at Portsmouth Museum
Carole Hartis & the Purdy family at the Dress to Distress at Portsmouth Museum.
Photos by Matthew Clark Photo: Matthew Clark
4. Dress to Distress at Portsmouth Museum
Arachi family at the Dress to Distress at Portsmouth Museum.
Photos by Matthew Clark Photo: Matthew Clark