Given reduced social interactions and economic distress, mental health has emerged as an important concern during COVID-19. This study estimates the prevalence of mental health problems during the first wave of COVID and identifies its determinants among the general population of Indian metropolitan cities.The study uses a Multiple Indicators Multiple Causes model to measure depression, anxiety and stress using observed indicators of these latent constructs, and to identify the socio-economic groups at risk of these disorders. The data was collected from 1,275 adults randomly selected from the list of mobile phone users in Bengaluru, Chennai, Delhi, Kolkata, Mumbai and Hyderabad. The Depression Anxiety Stress Scale was administered to the study participants.About 46, 24 and 48 percent of respondents reported symptoms of anxiety, depression and stress, respectively. Single respondents, members of minority groups, less educated and those belonging to large households are identified to be at-risk. Results also indicate a positive relationship between economic stress and mental illness.Although COVID has increased the psychological burden of the population, all persons reporting psychological disorders may not require clinical attention. While community-based support may be sufficient in general, monitoring is required to identify at risk persons who may require clinical support.