Objective To analyze the CT findings in renal angiomyolipoma with minimal fat and subtypes of renal cell carcinoma, and have a value evaluation of MSCT diagnosis and differential diagnosis of renal angiomyolipoma with minimal fat and subtypes of renal cell carcinoma. Methods A retrospective analysis was carried out on CT images of 21 cases of minimal fat renal angiomyolipomas and 98 cases of renal cell carcinoma (including 73 cases of clear cell renal carcinoma, 11 cases of papillary renal cell carcinoma, 9 cases of chromophobe renal cell carcinoma). The differences of CT imaging features were compared between minimal fat AML and renal cell carcinoma and they were analyzed by using statistical software (SPSS 18). Results TLC reconstruction showed ten cases of micro fat areas in the lipid-poor renal hamartoma group (47.6%) and two cases in the renal cell carcinoma group, with a significant difference (P<0.05). Degree of enhancement in corticomedullary phase (CMP) and the degree of attenuation in excretion phase of clear cell renal carcinoma were all larger than that of renal angiomyolipoma with minimal fat (P<0.05). Clear cell renal carcinoma was mostly shown heterogeneous enhancement while angiomyolipoma with minimal fat has substantially uniform strengthening (P<0.05). In the cortical phase, nephrographic phase and excretion phase, the degree of strengthening of angiomyolipoma with minimal fat was more than that of papillary renal cell carcinoma and chromophobe renal cell carcinoma (P<0.05), whereas there was no significant difference in excretion phase concerning the degree of attenuation (P>0.05), and the comparison regarding enhancement pattern was also of no significant difference (P>0.05). Conclusion The key to identify renal angiomyolipoma with minimal fat from renal cell carcinoma is to carefully determine whether micro-fat ingredients were present in the tumor by TLC reconstruction. For angiomyolipoma with invisible fat, the degree of tumor enhancement and the enhancement pattern were the important means of identification. Besides, the comprehensive analysis for the factors of subtype of renal cell carcinoma needs to be taken into account. Few atypical renal angiomyolipoma with minimal fat were difficult to be distinguished, which should be combined with a comprehensive analysis; if necessary, biopsy should be given to avoid misdiagnosis and thus leading to overtreatment.