When project learners are not able to fulfil their academic responsibilities and contribute to a project assignment, it may be assumed they are Not Pulling Their Weight, and therefore at risk of negative sanctions. Drawing on data derived from narrative accounts, interviews with learners in an online master's in business administration (MBA) program, together with documentation analysis, the study used classical grounded theory (Glaser & Strauss, 1967; Glaser, 1978; Glaser, 1992) to examine challenges professional graduate management learners may encounter in online group collaborations. The constant comparative method, an important analytical tool in grounded theory, yielded two core operatives, the first pertaining to the structural operational arrangements of a learning context, or Doing the Group Thing. The second core operative, Not Pulling Weight, is representative of a basic social process and consists of two problematic group-level phenomena, Pushed Out and Opting Out. In the 1st year of a program trajectory, uncertainty, pressure to excel, and the presence of punitive assessment measures may help explain the presence of marginalizing processes identified as hijackings. Hijackings were made up of four categories including: task, role, project, tampering and sub categories of editorial, and compensatory. A separate category under hijackings, are attempts to sabotage the efforts of project groups. By the 2nd year, a troublesome operative that disrupts and hampers project groups is the phenomenon of Opting Out. Opting Out refers to episodic or sustained acts of absenteeism and represents a continuum of effort-avoidance" manoeuvres (Salomon & Globerson, 1989, p. 90). The grounded theory study of Not Pulling Weight examined an under investigated phenomenon, that of excessive participatory practices in online group work. The theoretical framework emphasized the important mediating role of structural operatives that appeared to influence group level dynamics negatively. The study supports an emerging recognition in the networked management learning literature that there is a "dark side" with respect to online group collaboration and that groups can be places of inequity and oppression (Ferreday & Hodgson, 2008; Hodgson & Reynolds, 2005).