Persistent complex bereavement disorder (PCBD) is a disorder of grief included in DSM-5. Prolonged grief disorder (PGD) is included in ICD-11. Few studies have evaluated and compared criteria sets for DSM-5 PCBD and ICD-11 PGD. The current study explored and compared the dimensionality, prevalence rates, diagnostic agreement, concurrent validity, and socio-demographic and loss-related correlates of both criteria sets. Self-reported data were available from 551 bereaved individuals. Confirmatory factor analysis showed that for DSM-5 PCBD-symptoms, a three-factor model with distinct but correlated factors fit the data well; for ICD-11 PGD-symptoms a one-factor model yielded adequate fit. The prevalence of probable DSM-5 PCBD (8.2%) was significantly lower than ICD-11 PGD (19.2%). Both DSM-5 PCBD and ICD-11 PGD were significantly associated with concurrent overall grief and depression, and varied as a function of education and time since loss. ICD-11 PGD prevalence rates went down and agreement with PCBD-caseness went up, when heightening the number of symptoms required for an ICD-11 PGD diagnosis. This study was limited by its reliance on self-reported data and grief symptoms were derived from two scales. That notwithstanding, findings provide further evidence that differences exist between disturbed grief criteria in DSM-5 and ICD-11 that may negatively impact research and care.