This paper reports the results of a random sample survey of term-time employment amongst full-time undergraduates in four institutions. There is a belief that the incidence of employment is increasing, with detrimental effects for academic performance, but the supporting evidence is typically drawn from studies of specific institutions and/or specific groups of students. This paper offers a more widely-based estimate of the incidence of employment, analyses who works and why, and estimates the contribution of employment to student income. The paper suggests that the current focus on earnings and hours is limiting and that widely drawn ‘employment profiles˚s need to be identified and linked to academic constraints in order to identify the range of consequences of student employment.