Background: Understanding long-term retention rates and complications associated with different materials for fabricating pediatric crowns for primary teeth is crucial for material selection and optimizing clinical outcomes. Objective: This systematic review aims to descriptively analyze the crown-retention rates and complications associated with crown retention, as well as the biological and technical complications of pediatric crowns for primary teeth. The meta-analysis reported herein was performed to estimate long-term (3-year and 5-year) retention rates of these pediatric crowns fabricated using various materials. Methods: Using the PICOS paradigm, a systematic search was conducted between July and August 2023 in the Cochrane, EMBASE, and PubMed databases to identify randomized controlled trials (RCTs) and clinical (prospective and retrospective) studies reporting retention rates, complications of crown retention, and biological and technical complications. After selecting studies with a predefined set of selection criteria, data from included studies were used for a systematic review aimed at a descriptive analysis of factors associated with the failure of crowns for primary teeth. Data from the included RCTs were used for meta-analysis, wherein 3-year and 5-year crown-retention rates were estimated using Poisson regression models. Results: This systematic review included 13 RCTs and 5 clinical studies on dental crowns for primary teeth, involving 454 children (1172 crowns) in RCTs and 810 children (2667 crowns) in clinical studies. The median follow-up durations were 12 months for RCTs and 20.8 months for clinical studies, with a 10.6% dropout rate in RCTs. Retention rates varied: 77.8%-100% for compomer, 80.6%-100% for composite resins, 92.3%-100% for stainless steel, 78%-100% for strip crowns, and 86.4%-100% for zirconia. Poisson regression estimated 3-year and 5-year crown-retention rates, indicating good outcomes across materials. Complications included secondary caries, with up to 21.8% in zirconia, and marginal adaptation issues, with up to 22.2% in compomer. These findings highlight material-specific considerations necessary for optimizing outcomes in pediatric dental crown treatments. Conclusions: While retentive complications such as chipping, material loss, and fractures do occur across materials, crowns fabricated with compomer, composite resin, stainless steel, strip crowns, and zirconia all have clinically acceptable retention rates. However, the differences in biological and technical complications between materials may provide insights for selecting appropriate materials for pediatric crowns based on clinical considerations. Clinical Trial: PROSPERO CRD42023442266; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=442266