Objective Patient activation is important in the management of chronic diseases (CDs), especially hypertension and diabetes. The 13-item short form Patient Activation Measure (PAM13) is widely used, but data are lacking for China. The study aim was to assess the reliability and validity of the PAM13 in Chinese patients with hypertension and/or diabetes in a community management setting. Methods A cross-sectional survey was conducted at four community health centres in Kunming (Yunnan province, China) Participants were patients (n = 519) with hypertension and/or type 2 diabetes mellitus being managed at the community health centres. Patient activation was measured using the Chinese version of the PAM13. Reliability and validity were tested using Cronbach's alpha and confirmatory factor analysis. Results The male to female ratio was 1:1.65. In total, 307 (60.3%) patients had <= 9 years of education and 213 (41.8%) had a low household income (<= 5000 RMB/month). Cronbach's alpha was 0.920 and item-total correlations ranged from 0.535 to 0.714. Confirmatory factor analysis showed a good fit to the data. Conclusions The PAM13 shows good reliability and validity for measuring patient activation in Chinese patients with CDs (hypertension and/or diabetes).