Prolonged grief disorder (PGD), characterized by severe, persistent and disabling grief, is newly included in the International Classification of Diseases 11 (ICD-11). Receiving a PGD diagnosis could lead to stigmatizing public reactions (i.e. public stigma), yet research on this topic is limited. Additionally, while there is evidence that experiencing suicide bereavement causes public stigma, no studies to date have investigated the interaction between PGD and cause of death on public stigma. To fill these knowledge gaps, this experimental study tested if a PGD diagnosis (vs. no diagnosis) and experiencing suicide bereavement (vs. homicide and natural loss) cause public stigma. Three hundred and seventeen adults from the general population were randomly assigned to read one of 6 different vignettes of a person with and without PGD who had lost a spouse through a suicide, homicide or a stroke. After reading a vignette, negative attributions, emotional reactions, and desire for social distance were assessed. Notably, only persons with PGD were attributed relatively more negative characteristics, and elicited more anger, anxiety and pro-social emotions, and a larger preferred social distance in participants. This study supports the claim that PGD causes public stigma, but nuances claims that suicide bereavement induces public stigma.