To investigate SARS-CoV-2 (the virus causing COVID-19) infection and exposure risks among grocery retail workers, and to investigate their mental health state during the pandemic, this cross-sectional study was conducted in May 2020 in a single grocery retail store in Massachusetts, USA. Among 104 workers tested, 21 (20%) had positive viral assays. Seventy-six percent of positive cases were asymptomatic. After multi-variate adjustments, employees with direct customer exposure had an odds of 4.7 (95% CI 1.2 to 32.0) being tested positive for SARS-CoV-2, while smokers had an odds of 0.1 (95% CI 0.01 to 0.8) having positive assay. As to mental health, the prevalence of anxiety and depression was 24% and 8%, respectively. Employees with direct costumer exposure were 5 times more likely to test positive for SARS-CoV-2.