This article contributes to the growing evidence based on well-being in doctoral study. It draws on 35 qualitative, in-depth interviews to explore how the well-being of an understudied group--working doctoral student mothers--is affected when undertaking part-time PhDs. While there is a growing literature on the research student experience and an increased awareness of mental health issues in doctoral study, there has been little exploration of the experiences of part-time PhD students. Moreover, this is particularly true of mothers undertaking doctorates on a part-time basis. The experiences of this sub-group of research students constitute the gap to which this paper responds. It explores the consequences of having to straddle a number of competing domains and examines how the gender role conflict, marginalisation and lack of support experienced by doctoral student mothers impact their psychological, physical and social well-being. The article concludes with a number of recommendations that institutions may wish to consider.