BackgroundIntestinal parasitic infections are a major health problem worldwide. In Kenya intestinal parasitic infections are highly prevalent especially in prisons due to poor and/or inadequate infrastructure. The aim of this study was to establish the risk factors associated with intestinal parasites infection among inmates of Kisii prison, Kisii county, Kenya.MethodsFresh stool samples of 384 inmates in Kisii prison aged 20 years and above, were screened for intestinal parasitic infections between February and August 2015. Stool samples were processed using direct fecal smear and formol-ether sedimentation techniques for confirmation then they were examined microscopically. Multiple logistic regression analysis was used to establish the relationship of various factors and practices with the occurrence of intestinal parasites. The differences were considered statistically significant at P < 0.05.Results and discussionOf the 384 inmates screened, 95 (24.7 %) were infected with one or more intestinal parasites. Of the positive inmates, 58 (15.1 %) were infected with one species of protozoa while 24 (5.2 %) were infected with at least one species of helminthes and 13 (3.5 %) had mixed infections of species of intestinal parasites. Washing of hands before meals and after visiting toilets significantly reduced risk of infections (P < 0.05). The level of education was inversely related to the risk of intestinal parasites infection where by inmates at post primary education were least infected with intestinal parasites infection as compared to unschooled inmates (P < 0.05). Wearing of shoes was seen to significantly reduce parasitic infections (P ≤ 0.05). Duties assigned to inmates did not significantly determine the risk of intestinal parasitic infection (P > 0.05). Male inmates had significantly more intestinal parasites infections 57 (21.8 %) compared to females 28 (8.1 %) (P < 0.05). Inmates within ages 20–29 years were more infected (11.3 %) compared to the age group of >60 years (0.6 %) (P < 0.05). There was no statistical significant difference between the number of infections among the length of the jail terms (P < 0.05).ConclusionsPrevalence of intestinal parasites was high among inmates in the study area than the general population. Practices like wearing of shoes, washing of hands before meals after visiting a toilet and level of education affect the spread of the infections.