•Generally similar adverse event profile with the general population.•No cases of anaphylaxis or life-threatening reactions after vaccination.•Adverse events more prevalent in those 55 years old and younger.•Adverse events less prevalent in mild EDSS scores.•No increase in relapse rate after vaccination was detected. The aim of this study was to evaluate the safety of Sinofarm vaccine (BBIBP-CorV) in patients with multiple sclerosis (pwMS). This study was conducted on pwMS patients in Isfahan, Iran. All participants received two doses of BBIBP-CorV (Sinopharm vaccine). Demographic information and data on vaccine side effects were collected after each dose using questionnaires. All patients that recorded worsening of MS symptoms were evaluated and those with true relapse were treated with IV methyl prednisolone. Of the 1538 patients, 1151 (74.8%) were female and the mean age was 40.45 ± 9.74. The average disease duration was 10.38±6.81 years and 76.1% of participants had RRMS. 92.8% of the participants were using DMTs and mean EDSS was 2.06 ± 3.16. 54.2% (833 patient) reported at least one adverse event after the first dose of vaccine and 46.8% (720 patient) after the second dose; in both cases going away in a few days. Most prevalent adverse events after both doses were injection site pain, headache, myalgia, fever and fatigue. Adverse events were more prevalent in younger and less prevalent in mildly disabled patients. There were seven cases of Covid-19 infection between the first and second vaccination dose, and eight cases during one-month follow –up after the second dose, none of whom needed mechanical ventilation. Ten patients after first dose and thirteen patients after the second dose experienced acute relapse. A patient had two relapses, one after each vaccine dose that were clinically and radiologically confirmed. The first relapse occurred seven days after the first vaccination with hemiparesis and other relapse, 14 days after the second dose with diplopia, hemiparesis and ataxia. Adverse events in pwMS following vaccination with Sinopharm vaccine was similar to the general population, which were more common in younger patients and less common in those with mild disability. As no increase in relapse rate after vaccination was detected, Sinopharm vaccine was safe in MS patients.