Objective: Religious delusions (RDs) tend to occur relatively often in patients with affective or non-affective psychosis. Few studies exist about RDs in later life. The current study explores (1) the distribution of RDs across diagnosis, (2) how RDs relate to other types of delusions, and (3) how RDs relate to several dimensions or characteristics of delusions. Methods: Inpatients and outpatients in a Geriatric Psychiatry Department in the Netherlands (N = 155; mean age 76.5 years), and who were diagnosed with an affective or non-affective psychotic disorder, participated in semi structured diagnostic interviews, using the Schedules for Clinical Assessement in Neuropsychiatry 2.1. Results: Religious delusions were most common among patients with psychotic depression (47%) and schizophrenia (32%). The RDs frequently co-occurred with other types of delusions. When combined with delusions of grandeur, RDs were more often classified as bizarre and were accompanied by higher levels of positive psychotic symptoms. When combined with delusions of guilt, RDs were associated with higher levels of distress and a shorter disease duration. The delusional characteristics bizarreness, frequency of psychotic symptoms, and degree of distress were more prevalent for RDs than for any other type of delusion. Conclusions: The current study suggests that the prevalence of RDs in older adults is particularly high in late life psychotic depression. Also, in later life, RDs can be perceived of as independent marker of complex psychotic states, and as a denominator of severe arousal with respect to existential concerns.