BACKGROUND This study aimed to explore the association of angiotensin converting enzyme (ACE) gene insertion/deletion polymorphisms with left ventricular hypertrophy (LVH) in Han and Uighur hypertension-OSAHS (obstructive sleep apnea hypopnea syndrome) patients in China. MATERIAL AND METHODS A total of 162 Han and 72 Uygur patients with hypertension-OSAHS were independently subdivided into an LVH group and a non-LVH (NLVH) group based on the left ventricular mass index. The insertion/deletion polymorphisms of ACE gene were determined by polymerase chain reaction. The association of ACE gene insertion/deletion polymorphisms with LVH was assessed by chi-squared test. Logistic regression analysis was performed to obtain the odds ratios and 95% confidence intervals for the risk of LVH after adjusting for confounding factors. RESULTS In Uighur patients, the distributions of D allele and DD genotype showed significant differences between the LVH group and the NLVH group. The difference of DD genotype remained significant after multivariate adjustment. In contrast, no significant differences were observed in the distributions of D allele and DD genotype between the LVH group and the NLVH group in Han patients. Moreover, moderate-severe OSAHS was an independent risk factor for LVH. CONCLUSIONS D allele and DD genotype of ACE gene are possible genetic markers for the risk of LVH in Uighur but not Han hypertension-OSAHS patients.