A thematic literature review was undertaken to identify methodological aspects in the assessment of safety culture and critically examine how these have been addressed in hospital-based studies of safety culture, for the period 1999-2012. The literature search included an electronic database search (BNI, CINAHL, EMBASE, MEDLINE and PsycINFO), access to websites of organizations dedicated to the enhancement of patient safety, and a manual search of reference lists of the papers included. The analysis of the 43 records included in the review revealed that discussion regarding the measurement of safety culture in the hospital setting revolves around three methodological areas, namely: research approaches; survey tools for data collection; and levels of data aggregation. To advance these discussions, robust research is needed to clarify what dimensions belong to the core of safety culture and what the main sources of safety culture variability are. Studies using a mixed methods approach to assess safety culture would be useful, since they permit the in-depth research necessary to depict the multiple components of this construct. © 2014 Elsevier Ltd.