Search filters can support qualitative evidence of information retrieval. Various search filters are available for the bibliographic databases PsycINFO and CINAHL. To date, no comparative overview of validation results of search filters verified with an independent gold standard exists. Identified search filters for PsycINFO and CINAHL were tested for plausibility. Gold standards were generated according to the relative recall approach using references included in an overview of systematic reviews of qualitative studies. All included references were collected and checked for indexing in PsycINFO and CINAHL. Validation tests for each search filter were conducted in both databases to determine whether the references of the gold standards could be retrieved or not. Twelve search filters for PsycINFO and fifteen for CINAHL were validated. The complexity and design of these search filters vary, as well as the validation results for the databases. When locating primary studies of qualitative research, the best sensitivity and precision ratio (among filters with a sensitivity of >80%) was achieved with a filter by McKibbon et al. for PsycINFO and a filter by Wilczynski et al. for CINAHL. Project-specific requirements and resources influence the choice of a specific search filter for PsycINFO and CINAHL. Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.