ObjectiveTo investigate the distribution of HCV genotypes in 383 patients with HIV/HCV coinfection in Guizhou, China and the effect of coinfection on HIV viral load, CD4+ T lymphocytes, and platelet count (PLT), and to provide a basis for individualized treatment of patients with HIV/HCV coinfection. MethodsRelated clinical data were collected from 383 patients with HIV/HCV coinfection who were treated in Guiyang Public Health Clinical Center from March 2015 to December 2019, and HCV genotype, HIV viral load, CD4+ T lymphocytes, and PLT were determined. A total of 1068 patients with HIV alone were enrolled as control. The Kruskal-Wallis H test was used for comparison between multiple groups, the Wilcoxon rank-sum test was used for comparison between two groups, and the Bonferroni method was used for further comparison between two groups; the chi-square test or the Fisher’s exact test was used for comparison of categorical data between groups. ResultsAmong the 4664 patients with HIV infection, 383 (8.21%) had HCV coinfection, and the main HCV genotypes were genotype 6a (35.51%), genotype 3b (27.42%), and genotype 1b (21.41%), followed by genotypes 3a (1332%), 1a (1.31%), 2a (0.52%), 6n (0.26%), and 6xa (0.26%). The most common route of infection was intravenous drug addiction (72.59%), followed by sexual contact (24.80%). Compared with the patients with HIV infection alone, the patients with HIV/HCV coinfection had a significantly higher HIV RNA load and significantly lower CD4+ T lymphocytes and PLT (Z=6.716, 11.813, and 9.192, all P＜0.05). Among the patients with coinfection, the patients with HCV genotype 3b had the highest HIV RNA load and the lowest CD4+ T lymphocytes and PLT, while the patients with HCV genotype 1a had the lowest HIV RNA load and the highest CD4+ T lymphocytes (all P＜0.05). Among the patients with different clinical stages, the patients with compensated cirrhosis had the highest HIV RNA load, the patients with chronic hepatitis C had the lowest HIV RNA load, the patients with end-stage liver disease had the lowest count of CD4+ T lymphocytes, and the patients with chronic hepatitis C had the highest PLT (all P＜0.05). ConclusionThe distribution of HCV genotypes is diverse in the patients with HIV/HCV coinfection in Guizhou, and HCV strains with genotypes 6a, 3b, and 1b are the main epidemic strains. Intravenous drug addiction is the main route of infection. Coinfection may affect HIV replication and immune status, with a significantly marked effect on HCV genotype 3b and liver cirrhosis or end-stage liver disease.