Resumen Objetivos: Caracterizar manifestaciones clinicas y factores de riesgo asociados a Cryptos- poridiosis. Materiales y metodos: Se realizo un estudio descriptivo transversal en 423 pacientes, con analisis macroscopico y microscopico de muestras fecales, para identificar manifestaciones clinicas y factores de riesgo asociados a Cryptosporidiosis en tres municipios del Atlantico y su capital en un periodo de 4 meses. Se identificaron ooquistes de Cryptosporidium spp. despues de tenirse con Ziehl-Neelsen modificado. Se comparo el metodo de concentracion NaCl saturado con el metodo en fresco, para la deteccion de parasitos intestinales en 279/423 (66.0%) pacientes. El analisis estadistico se realizo usando EPI-INFO 6.04. Resultados: La prevalencia de Cryptosporidium spp. fue 1.9% (8/423). Se encontraron asociaciones estadisticas entre cryptosporidiosis y fiebre (p=0.01), sangre en muestras fe- cales (p=0.01) y presencia de animales domiciliarios (p=0.02). La mayoria de los pacientes (267/423:20.3 %) fueron positivos para parasitos intestinales. Los parasitos identificados con mayor frecuencia fueron protozoos no enteropatogenos, Entamoeba coli (118/423: 27.9%) y Endolimax nana (86/423: 20.3%), seguido de Blastocystis hominis (76/423: 18%), Entamoeba histolytica/dispar (28/423: 6.6%) y Giardia lamblia (23/423: 5.4%). Ascaris lumbricoides (6/423: 1.4%) fue el helminto identificado con mayor frecuencia. Una sensibilidad/especificidad de 99.45/95.2% y 87.5%/99.6% se obtuvo para protozoos y helmintos respectivamente usando el metodo de NaCl saturado. Conclusiones: Los pacientes con cryptosporidosis tuvieron fiebre y muestras fecales san- guinolentas. Probablemente fueron infectados por animales domesticos. Microscopicamente, la utilizacion de la tincion Ziehl Neelsen modificado fue esencial para la identificacion de ooquistes de Cryptosporidium spp. El metodo de NaCl saturado concentro eficientemente los parasitos. Palabras claves: Cryptosporidium spp., Ziehl-Neelsen modificado, parasitosis in- testinales. Abstract Objectives: To characterize the clinical manifestations and risk factors associated with cryptosporidiosis. Materials and methods: A descriptive study was performed on 423 patients, with mac- roscopic 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 stain- ing 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 Endoli- max 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 lumbricoi- des (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. Key words: Cryptosporidium spp., modified Ziehl-Neelsen stain, intestinal parasi- tesis.