Although developmental coursework can play an important role in preparing many adult students to succeed in college, its long term impact is not well understood. The purpose of this research was to add to the small body of knowledge about developmental coursework, by examining its relationship to the graduation rates of adult students. The study used a quasi-experimental design and was grounded in Knowles' andragogy theory, Mezirow's transformation theory, Bean and Metzner's model of student persistence and attrition, and the Seidman formula for student success. Beginning with a total population of 2,618 adult students entering 2-year institutions in Ohio from 1999 to 2001, a purposive sample of graduates was taken from institutions that used the COMPASS placement test to guide students into developmental coursework. Using the likelihood ratio chi-square, a comparison of the length of time to graduation showed a significant difference ( L 2 (4, N = 314) = 29.44, p = .000006) between students who took developmental coursework ( n = 191) and students who did not ( n = 123). The post hoc analysis of standardized residuals revealed that the key difference between the groups existed only for year 2, which could be explained by the additional time required to complete developmental coursework. Further examination suggested that adults who took developmental coursework tended to persist and graduate at a higher rate - over 3% more than adults who did not take developmental coursework. The graduation rates for adult students who took developmental coursework were also analyzed by gender and race, but no significant differences were found for either grouping, in contrast to previous research. As an issue to social change, these results demonstrate that underprepared adults can graduate when provided with academic support through developmental courses.