Background: Cryptosporidium parvum is an intracellular coccidial protozoa that can lead to life-threatening impacts in immunocompromised hosts. Atorvastatin may be used to treat human cryptosporidiosis. Nanomedicine developments appear promising in treatment of cryptosporidiosis. Purpose: The aim of this work is to evaluate the efficacy of atorvastatin loaded on nanoparticles on treatment of cryptosporidiosis. Methods: Cryptosporidium oocysts were obtained by collection of stools from naturally infected calves. Both Nitazoxanide (500 mg/kg/day) and atorvastatin (40 mg/kg/day) either alone or loaded on silver nano particles (SNP) were given to the selected immunosuppressed 110 mice. Assessment of drugs effect was done by parasitological, histopathological and serological assessment. Results: The highest group in reduction of numberof oocysts recorded in combination group of atorvastatin and nitazoxanide loaded on SNP (95.1%). The highest level of serum GSH was recorded in negative control group (26±.5) and the least value recorded in positive control group (7.1±0.9). Combination of nitazoxanide and atorvastatin loaded on SNP achieved the highest increase in serum GSH level among treated groups (24.8±1.4). Examination of sections from different treated groups showed remarkable decrease in intestinal inflammation with decreased number of Cryptosporidium oocysts with best results in groups BVII (combination of atorvastatin and nitazoxanide) and BVIII (combination group of atorvastatin and nitazoxanide loaded on SNP) showing significant statistical difference compared to positive control group BII. Conclusion: atorvastatin (either alone or loaded on silver nanoparticles) in combination with nitazoxanide seems to be more efficient and could be a good candidate in the treatment ofcryptosporidiosis.