Intestinal parasitic infections (IPIs) remain a public health issue in developing countries where overcrowded settlements and poor sanitation are general rule. Due to paucity of IPIs data in known overcrowded Cameroonian prisons, this cross-sectional study conducted in 2015 in the New-Bell Central Prison (NBCP) aimed to establish biodiversity, prevalence and risk factors of intestinal protozoan and helminthe infections among inmates. Fresh stool samples collected from the NBCP volunteered inmates were laboratory examined microscopically as fresh mounts plus iodine, Kato-Katz smears, formalin-ether concentration and modified Ziehl-Nelseen stained sediments. Of a total 374 inmates who participated in the study, overall IPIs prevalence was 39.3%. Helminthe and protozoa prevalence was 16.6% and 24.6% respectively. Parasites species were recorded at following prevalence: Ascaris lumbricoides (10.4%), Trichuris trichiura (5.1%), Schistosoma mansoni (0.5%), Entamoeba histolytica/dispar (14.2%), Entamoeba coli (16.6%), Giardia intestinalis (7.2%), Chilomastix mesnili (2.4%), Blastocystis spp (2.1%) and Cryptosporidium sp (4.3%). Co-infections by two or three parasites were recorded among parasitized inmates. Overall IPIs prevalence was not significantly influenced by gender, age, detention duration, education level, handwashing practices, sanitation and drinking water source. However, highest IPIs prevalence occurred in males aged 30 to 49 years old, less than one year detainees, latrine users and those who drank borehole water. Systematic handwashing practices and education level did not influence significantly IPIs prevalence. All helminthe infections were of light intensities. Inmates in the New Bell central prison were parasitized by several species of protozoa and intestinal worms in varying prevalence depending on the detention period, the sex, the age and hygiene. A regular IPIs control among prison inmates was recommended to the NBCP managers to prevent related morbidity.