Purpose: This literature review identifies instruments for diagnostic assessment of cognitive impairment in prison populations. The purpose of this paper is to promote procedures for early screening and identification of cognitive impairment using instruments appropriate to prisons. Design/methodology/approach: A targeted literature review identified studies on screening and diagnostic assessment of adults in jails, prisons, police watch-houses (custody suites), rehabilitation facilities and forensic settings or community settings for offenders. Discriminant validity, suitability, reliability and feasibility of instruments in correctional and forensic settings are presented. Findings: From 135 peer-reviewed articles relating to diagnostic assessment of cognitive impairment, 15 instruments were considered appropriate for use in prison settings. Research limitations/implications: Selection of instruments for prison use considers suitability of the instrument(s) and clinical workforce capability. Cultural and gender validity of the instrument, its feasibility for use in the prison environment and cost and time to administer are also important. Using appropriate tools as part of a staged and targeted process in the screening and diagnosis of cognitive impairment is demonstrated by two case vignettes presented in this paper. As this was a desk review, the authors did not evaluate the instruments. Originality/value: Identification of instruments that are suitable for diagnosis of cognitive impairment in forensic populations informs the rehabilitation of offenders with cognitive impairment in prison and upon release to probation and parole.