The illegal wildlife trade, especially of live animals, is a major threat to slow lorises. Large numbers of confiscated slow lorises are sent to rescue facilities. We aimed to describe the occurrence and types of abnormal repetitive behaviours (ARBs) in 36 confiscated Bengal slow lorises (Nycticebus bengalensis), and examined factors influencing the occurrence of ARBs. We recorded behaviours of the slow lorises using instantaneous scans every 5 min from 19: 00 to 06: 00 h, and observed 6 types of ARBs in 14 (38.9%) individuals. Each individual exhibited 1 type of ARB. The most prevalent ARBs were pacing, rocking and up-down movement, and represented 29.9 ± 13.6% of the activity budget. Sex did not significantly influence the occurrence of ARB. Animals who had been at the centre for longer had a greater tendency to exhibit ARBs, but this was not statistically significant. We suggest that housing slow lorises in large semi-natural enclosures with conspecifics may reduce ARBs. Other factors potentially influencing ARBs, such as cage size, should be further investigated.