Background: Cerebral microbleeds (CMBs) detected by gradient-echo MRI have been proven to be a potential risk factor for further bleeding, while the association between CMBs and the first onset of intracerebral hemorrhage has not been well investigated. Purpose: To analyze the association between CMBs and the first onset of primary intracerebral hemorrhage (pICH). Material and Methods: Two hundred and two consecutive inpatients with ICH and 234 consecutive outpatients without ICH as control group were enrolled in this study. MR imaging including T2*-GRE, T1W, T2W and fluid attenuated inversion recovery (FLAIR) sequences were performed to detect CMBs and other abnormalities. Prevalence, distribution, and grades of CMBs, as well as the location and size of the intracerebral hematoma were analyzed, respectively. Comparison was made between pICH and control group. Logistic analysis was performed to evaluate the association between CMBs and ICH. The correlation between hematoma size and CMBs grade/numbers was analyzed. Results: CMBs were detected in 140 patients in pICH (69.3%) group and 62 patients in control group (26.5%). The incidence of CMBs in pICH group was significantly higher than that in control group (P < 0.0001). As the logistic regression analysis results, CMBs was the risk factor associated with ICH, with modulation OR value of 8.363 (95% CI 5.210-13.421). The volume of ICH with CMBs was 12.57 +/- 17.23 mL, and the volume of ICH without CMBs was 17.77 +/- 26.97 mL. Negative correlation was demonstrated between CMBs number and ICH volume (r(s) = -0.1769, P = 0.0118), as well as between CMBs grade and hematoma volume (r(s) = -0.1185, P = 0.1557). Conclusion: CMBs may be an independent risk factor for the first onset of intracerebral hemorrhage.