This paper examines the influence of ethnic background on organizational status attainment. The data are taken from a national sample of 2,755 Roman Catholic diocesan priests and bishops. The sample is divided into seven ethnic categories: Irish, German, French, Italian, Anglo-Saxon, Polish, and other. Controlling for the overall distribution of status positions within the diocese and the individual's age/seniority, a "non-preferential" model of status attainment is constructed. Average expected status on the basis of this non-preferential model for these ethnic groups in seven different regions of the country is compared to average actual status. Although we found three isolated cases of particular ethnic groups in specific regions doing significantly poorer in status attainment than predicted by the non-preferential model, the only consistent effect of ethnicity found across the entire sample is a slight advantage enjoyed by Irish clergy. No significant effect was associated with belonging to the largest ethnic group in a diocese. The very small advantage enjoyed by the Irish suggests that Irish domination of the Catholic hierarchy in the United States is maintained less by selective promotion within the ranks of the clergy and more by a disproportionate recruitment of Irish priests at the entrance levels of the organization. Disproportionate recruitment and preferential promotion are discussed as alternative mechanisms of domination within organizations.The issue of the relative impact of ascribed versus achieved attributes in the organizational status attainment process has been a perennial theme in the study of occupations, careers, and organizations. In Weber's ( 1947) classic treatment of the bureaucratic career, mobility within a hierarchy is considered functionally necessary for insuring motivation of workers toward high performance, which, in turn, is functionally important for organizational stability. If the bureaucratic system is to proceed, however, opportunities for promotion must be tied to rational achievement criteria and not to any ascribed characteristics of the individuals involved. The genius of the bureaucratic system is its ability to perform effectively regardless of the ascribed characteristics of its members.Many studies have demonstrated that members of formal organizations do not act according to the rational ideals of Weber's bureaucratic model, and ethnicity is one of the traits which may compete with universalistic criteria in the organizational stratification system. Thus, Dalton's ( 195 1) classic study of industrial managers concludes that conformity to the ethnic and religious background of those in the upper strata is crucial for advancement. More recently, Beattie and Spencer ( 197 1 ) discovered that Canadian federal bureaucrats having a French-