This article presents a systematic review identifying variables and their prognostic value for return to work (RTW) after traumatic brain injury (TBI). RTW has been identified as being a key goal following TBI, with estimates ranging from 10% to 70%. Prediction of postinjury employment is important for planning rehabilitation and structuring individualised vocational services. Studies examining prognostic factors were identified by searching four electronic databases, until June 2006. Searches yielded 1948 studies of which 55 met inclusion criteria and were subsequently rated for methodological quality. Mean methodological score for included studies was 3.9/6 (SD 0.9, range 1–6). Analysis focused on a subset of 27 studies which provided sampling from all three domains of preinjury, injury and early postinjury variables. Few studies considered preinjury variables, apart from simple demographics. Only five studies considered preinjury employment, which was a significant predictor in each case. Severity of injury variables were invariably examined, but were significant predictors in only 8/27 studies (30%). For early postinjury variables, 14/27 studies entered cognitive variables with 12/14 (86%) identifying them as significant predictors; 3/27 studies examined neurophysical variables, with 2/3 (67%) studies finding them significant; and 12/27 studies examined multidimensional/participation variables which were statistically significant individual predictors in 8/12 (67%) cases. The results are discussed in the context of methodological issues encountered during the course of the review that require addressing in future studies.