This study aimed to investigate the association between physical activity and persistent anti-SARS-CoV-2 antibodies 6 months after two-dose schedule of CoronaVac in autoimmune rheumatic diseases (ARD) patients. This was a prospective cohort study within an open-label, single-arm, phase 4 vaccination trial (clinicaltrials.gov #NCT04754698), conducted at a tertiary referral hospital in Sao Paulo, Brazil. ARD patients aged ≥18 underwent a two-dose schedule of CoronaVac (Sinovac Life Sciences, China). Persistent immunogenicity 6 months after the full-course vaccination was assessed using seroconversion rates of total anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG (GMT), and frequency of positive neutralizing antibodies (NAb). Physical activity was assessed trough questionnaire (active being defined as ≥150 min/week of moderate-to-vigorous physical activity). Physically active (n=421) and inactive (n=327) ARD patients were similar for most characteristics; however, active patients were significantly younger (p<0.001), had less chronic inflammatory arthritis (p<0.001) and less frequently used biologic agents (p<0.001) than inactive ones. Six months after full-course vaccination, being male (p<0.001), use of prednisone (p<0.01) and biologics (p<0.001) were associated with poor immunogenicity, while being physically active was associated with better humoral response (p<0.01). Adjusted point estimates from logistic regression models indicated greater odds of seroconversion rates (OR: 1.5 [95%CI: 1.1 to 2.1]) and NAb positivity (OR: 1.5 [95%CI: 1.0 to 2.1]) in physically active patients and approximately 43% greater GMT (42.8% [95%CI: 11.9 to 82.2]) than inactive ones. In conclusion, among immunocompromised patients, being physically active was associated with an increment in antibody persistence through 6 months after a full-course of an inactivated SARS-CoV-2 vaccine.