Objectives: To characterize the clinical manifestations and risk factors associated with cryptosporidiosis. Materials and methods: A descriptive study was performed on 423 patients, with macroscopic and microscopic faecal sample analyses, to identify the clinical manifestations and risk factors associated with cyptosporidiosis in 3 towns and the principal city in Atlantico (Colombia) over a 4-month period. Cryptosporidium spp oocysts were identified after staining with modified Ziehl-Neelsen. A saturated NaCl parasite-concentration method was also compared with wet-mount method for the detection of all intestinal parasites in 279/423 (66.0%) patients. Statistical analyses were performed using EPI-INFO 6.04. Results: The prevalence of Cryptosporidium spp. was 1.9% (8/423). Statistical associations were found between cryptosporidiosis infections and fever (p=0.01), blood in the faecal samples (p=0.01) and the presence of household animals (p=0.02). Most of the patients (267/423: 63.1%) were positive for intestinal parasites. The most commonly identified parasites were the non-pathogenic protozoa, Entamoeba coli (118/423: 27.9%) and Endolimax nana (86/423: 20.3%), followed by Blastocystis hominis (76/423: 18%), Entamoeba histolytica/dispar (28/423: 6.6%) and Giardia lamblia (23/423: 5.4%). Ascaris lumbricoides (6/423: 1.4%) was the most common helminth identified. Sensitivities/specificities of 99.4%/95.2% and 87.5%/99.6% were obtained for protozoa and helminths respectively using the saturated NaCl method. Conclusions: Patients with cryptosporidiosis had fever and bloody faecal samples, and were probably infected by domestic animals. Microscopy, using the modified Ziehl-Neelsen stain, was essential for Cryptosporidium spp. oocyst identification. The saturated NaCl method efficiently concentrated the parasites.