To explore the clinical characteristics of diabetes mellitus (DM) induced by atezolizumab in cancer patients and provide evidence to guide the rational clinical application of atezolizumab. We conducted a retrospective study on diabetes induced by atezolizumab, analyzing it by retrieving the case reports in the database from 2016 to 8 April 2025. Overall, the median age of the 30 atezolizumab induced DM patients was 67 years (44-85 years), among which 19 patients (63.3%) were male. Atezolizumab induced DM occurred at a median of 147 days (15-600 days) after the treatment with atezolizumab. 12 patients (40.0%) had ICI-T1DM, 10 patients (33.3%) had ICI-FT1DM, 8 patients (26.7%) had ICI-DM. The HLA typing test information provided by 10 patients showed that these patients carried susceptible genes related to DM. After DM was induced by atezolizumab, insulin or a combination of insulin and oral hypoglycemic agents was used, achieving a good effect in blood glucose levels. 10 patients (33.3%) continued to use atezolizumab after glycemia improvement. Among the 30 patients, except for 4 patients who died due to tumor progression (3 cases) and liver injury (1 case), the rest all alive or not reported their survival status. In conclusion, when administering atezolizumab treatment for cancer patients, it is recommended to monitor blood glucose levels regularly. In case atezolizumab induced DM occurs, insulin should be administered to regulate blood glucose.