This systematic review of prospective cohort studies investigated the evidence for prognostic factors for poor recovery in recent-onset nonspecific low back pain (NSLBP). Medline, Cinahl, Embase, PsychINFO, and AMED databases were searched and citation tracking was performed. Fifty studies met the inclusion criteria. Bivariate and multivariable prognostic factor/outcome associations were extracted. Two reviewers independently performed data extraction and method quality assessment. Where data were available, odds ratios for bivariate associations were calculated and meta-analysis was performed on comparable prognostic factor/outcome associations. Despite the number of studies that have investigated these prognostic factors, uncertainty remains regarding which factors are associated with particular outcomes, the strength of those associations and the extent of confounding between prognostic factors. This uncertainty is the result of the disparate methods that have been used in these investigations, incomplete and contradictory findings, and an inverse relationship between study quality and the reported strength of these associations. The clinical implication is that the formation of clinically useful predictive models remains dependent on further high-quality research. The research implications are that subsequent studies can use the findings of this review to inform prognostic factor selection, and that prognostic studies would ideally be designed to enhance the capacity for findings to be pooled with those of other studies.