Forty to sixty percent of students who begin doctorates in selective colleges and universities do not persist to graduation. Although numerous research studies have focused on doctoral attrition and persistence, there have been no systematic studies because, among other reasons, there are no nationwide databases on attrition as there are for doctoral completion; also colleges and universities do not routinely and systematically collect data on attrition. This study synthesizes findings from the literature in an effort to develop a comprehensive understanding of doctoral student attrition and persistence. A new qualitative methodology-meta-synthesis was used to sort and integrate findings from the large body of research on doctoral student persistence. The sample for the study consists of 118 research studies completed between 1970 and 1998. Findings indicate that: (1) attrition and persistence rates vary widely depending on field of study, and even more widely depending on program of study; (2) departmental culture affects doctoral student persistence; (3) difficulties with the dissertation relate to attrition; (4) academic achievement indicators, with the exception of graduate record examination scores, are not effective predictors of degree completion; (5) employment and financial factors are poor indicators of persistence; and (6) retention rates vary widely among institutions. (Contains 168 references.) (RH)