BACKGROUND Fluoride varnish (FV) is widely recommended for caries prevention in preschool children, despite its anticaries benefits being uncertain and modest. Dentists often report using clinical practice guidelines (CPGs) as a source of scientific information. OBJECTIVE To identify and analyze recommendations for clinical practice on the use of FV for caries prevention in preschool children and to assess the methodological quality of the CPG on this topic. METHODS Two researchers independently used 12 search strategies and searched the first five pages of Google Search™ and three guideline databases for recommendations freely available to health professionals on the use of FV for caries prevention in preschoolers. Then, they retrieved and recorded recommendations that met the eligibility criteria and extracted the data. A third researcher resolved disagreements. Each included CPG was appraised using the AGREE II instrument. RESULTS Twenty-nine documents were included. Recommendations varied according to age, patients' caries risk, and application frequency. Of the six CPGs, only one scored above 70% in the AGREE II overall assessment. CONCLUSIONS Recommendations on the use of FV lacked scientific evidence, and CPGs were of poor quality. Application of FV is widely recommended despite recent evidence showing an uncertain, modest, and possibly not clinically relevant anticaries benefit. Dentists should be aware that it is necessary to critically appraise CPGs since they may be of poor quality.