Objectives: The aim of the study was to validate search filters for retrieval of clinical practice guidelines (CPGs) in MEDLINE, Embase, and PubMed. Study Design and Setting: A search for filters for identifying CPGs was conducted in Google and the InterTASC Information Specialists SubGroup Search Filter Resource. To retrieve a random sample of CPGs to test sensitivity and precision of the filters, we used the TRIP and Epistemonikos databases. The citations were screened independently by two researchers. The sensitivity and precision were calculated. Results: Five search filters were retrieved: two from the Canadian Agency for Drugs and Technologies in Health (CADTH), two from the University of Texas, and one from the MD Anderson Cancer Center Library. A total of 478 records were screened to identify 109 CPGs, which comprised the sample for testing sensitivity and precision. The sensitivity ranged from 87% to 98% for the five search filters and very low precision (!1%) across all databases. Conclusion: Knowledge users who are interested in retrieving all relevant CPGs can use the CADTH broad filter with the highest sensitivity. However, our analysis shows that it remains difficult to efficiently identify CPGs because of low precision of five search filters. We recommend searching guideline-specific resources as a more time-efficient approach than searching bibliographic databases.