Millions of people are grieving the loss of someone who died of COVID-19. However, there have been no screening tools developed to identify individuals who may be suffering from dysfunctional grief during the pandemic. Therefore, the objective of this study was to develop and evaluate the properties of the Pandemic Grief Scale (PGS), which is a brief mental health screener to identify probable cases of dysfunctional grief associated with a COVID-19 death. This 5-item scale, which was based on 831 adults who lost someone to COVID-19, demonstrated solid reliability (αs = 0.86), factorial validity (PCA and CFA support), and construct validity with strong correlations with suicidal ideation and substance use coping. The PGS measures COVID-19 grief equivalently across demographic groups, and discriminates well between persons with and without dysfunctional grief using an optimized cut score of ≥ 7 (87% sensitivity and 71% specificity). An alarming 66% of the sample scored in the clinical range. The PGS also demonstrates incremental validity by explaining 18% additional variance in functional impairment due to a COVID-19 loss beyond measures of depression and generalized anxiety. These results support the PGS as an efficient and valid screening tool for clinical research and practice during a pandemic.