The influences of course effort and outside (family, job, social) activities on grades earned in a college course were examined for 230 urban college students. Multiple measurements of hours of work, social and family activities, and course effort were collected over a semester. Path modeling revealed that cumulative GPA and course effort had significant and independent predictive paths with grades. Outside activities did not directly influence course grade. Job activities, however, negatively influenced course grade indirectly through reduced course effort and mediated the influence GPA exerted on course grade. Thus, work demands lessened course effort and lessened GPA-indexed potential for course success. Cumulative GPA positively influenced effort, and effort mediated part of the relation between cumulative GPA and grades.