Aim Of The Study: To study the menstrual irregularities in female healthcare workers in the age group of 18-45 years following COVID vaccination. A self-reporting questionnaire, was designed and after being validated, Method: was administered via email and telephonic interviews to female healthcare workers in the age group of 18-45 years as they were amongst the rst to receive the COVID vaccine. From AprilNovember 2021,132 respondents, mainly from Mumbai, some from Pune, Nashik & Aurangabad completed the questionnaire The questionnaire pertained to and gathered details of two consecutive menstrual cycles following the rst dose and the booster dose of the COVID vaccine. Result: Following the rst dose of the COVID vaccine, it was found that around 26% experienced delayed menses,14% reported menorrhagia and around 12% of the women experienced severe dysmenorrhoea. Following the booster dose, 31% reported delayed menses, 16 %reported menorrhagia and 11% experienced severe dysmenorrhea. Menstrual irregularities following the COVID va Conclusion: ccination (rst & booster dose) predominantly included delayed menses, menorrhagia, severe dysmenorrhoea than experienced otherwise, followed by early menses and scanty bleeding.