OBJECTIVE: To metasynthesize the results of qualitative studies on the factors that affect parents' participation in pain management for their infants during procedures in the NICU. DATA SOURCES: We conducted a literature search for articles published from 1976 through November 2019 using MeSH terminology in the following databases: MEDLINE, CINAHL Plus, EMBASE, PubMed, PsycINFO, Cochrane, Scopus, and Web of Science. All qualitative studies in which researchers explored parental participation and education in the NICU were included. STUDY SELECTION: A total of 29,937 articles were returned. Once we removed duplicates and limited results to qualitative studies, 48 articles remained. We excluded 41 articles because the studies reported were not conducted in NICUs, involved neonatal palliative care, or were review or opinion articles. We included seven articles for review. DATA EXTRACTION: Two authors reviewed all articles using the Critical Appraisal Skills Programme tool to assess study quality and independently scored each study. We reviewed and extracted authors, publication date, type of study, sample size, results, themes, and quotes and included these data elements in the analysis. DATA SYNTHESIS: We used a thematic synthesis technique to review the qualitative data, entered codes into NVivo software, and compared codes to create descriptive themes. From these descriptive themes, we generated four analytic themes: Learning to Parent a Hospitalized Infant, Stress and Anxiety, Health Care Providers as Gatekeepers, and NICU Environment. CONCLUSION: The four themes identified in this qualitative metasynthesis represent the factors that affect parents' abilities to participate in their infants' pain management. Further research is recommended to develop interventions that address these factors to optimize parents' participation in pain management for their infants during procedures in the NICU.