The use of psychological testing in the 175 U.S. Roman Catholic Marriage Tribunals was surveyed. The response rate was an adequate 36% (N = 63), comprising a nationally representative sample, although many tribunals responded to the questionnaire with limited information. The majority of tribunals employed clinical psychologists to conduct assessments for marital annulment petitions that invoke Canon 1095 (Psychic Incapacity) and/or when severe psychopathology was suspected in either marriage partner. The preferred assessment technique was an unstructured diagnostic interview, though a small number of psychological tests were also endorsed, the most frequent being the Minnesota Multiphasic Personality InventoryAaAeAeAu However, the decisions concerning whether to use psychologists, which cases to assign them, and what test(s) to use were idiosyncratic to each tribunal, in contrast to the highly structured procedural nature of these proceeding in canon law. Although this has drawn no attention in the research literature, psychologists appear to play an active, yet circumscribed, role in Roman Catholic Marriage Tribunals. No assessment guidelines or best practice procedures exist for psychologists involved in tribunal assessments. We recommend the development of a standardized screening procedure as well as a consistent national assessment battery using reliable and valid broad-band personality measures. Psychologists should consider such religious venues as new assessment opportunities after developing a knowledge base and cultural awareness for Roman Catholic issues.