Purpose - This paper aims to measure and analyse the wage gap between male part- and full-timers in the private sector of six European countries, i,e. Belgium, Denmark, Ireland, Italy, Spain, and the UK. Design/methodology/approach - Using a unique matched employer-employee data set providing harmonised information on six European countries (the 1995 European Structure of Earnings Survey), the empirical strategy is based on the estimation of standard Mincer wage equations and the Oaxaca and Ransom wage gap decomposition technique. First, individual gross hourly wages are regressed on a set of human capital variables only and second, a wider range of control variables related to e.g. occupation, sector of activity, firm size, and level of wage bargaining is inserted. Findings -The study finds that the raw gap in hourly gross pay amounts to 16 per cent of a male part-timer's wage in Spain, to 24 per cent in Belgium, to 28 per cent in Denmark and Italy, to 67 per cent in the UK and to 149 per cent in Ireland. Human capital differences explain between 31 per cent of the observed wage gap in the UK and 71 per cent in Denmark. When the whole set of explanatory variables is included in the wage regressions, a much larger part of the gap is explained by differences in observed characteristics (except in Italy). Research limitation/implications - Unfortunately, the paper is not able to correct for workers' potential self-selection into part-time and full-time employment. Results suggest that policy initiatives to promote lifelong learning and training are of great importance to help part-timers catch up with full-timers in terms of human capital. Moreover, except for Italy, they point to a persisting problem of occupational and sectoral segregation between men working part-time and full-time which requires renewed policy attention. Originality/value - Economic theory advances a number of reasons for the existence of a wage gap between part-time and full-time workers. Empirical work has concentrated on the wage effects of part-time work for women. For men, much less empirical evidence exists, mainly because of lacking data. This paper therefore makes a valuable contribution. The more so given that (to the best of our knowledge) there exists no cross-national evidence with respect to men's part-time wage penalty. [ABSTRACT FROM AUTHOR]