Background <p>Stainless steel crowns (SSCs) are widely used for restoring severely carious primary molars. However, clinical evidence comparing different commercially available SSC systems remains limited. This study aimed to compare the clinical success and parental satisfaction of two SSC systems, Kids Crown and NuSmile, in pediatric patients.</p> Methods <p>This retrospective observational cohort study included children aged 2–8&#xa0;years who received at least one SSC under general anesthesia and had a minimum follow-up of 6&#xa0;months. Clinical evaluations were performed by a single calibrated examiner and assessed crown retention, marginal adaptation, occlusion, proximal contact, gingival health, oral hygiene status, and biological or mechanical complications. Parental satisfaction was evaluated using a 5-point Likert-scale questionnaire. Non-parametric statistical tests were applied with a significance level set at <i>p</i> &lt; 0.05; all tests were two-sided.</p> Results <p>A total of 65 children (246 crowns) were included, with a mean follow-up of 20.12 ± 13.31&#xa0;months. Both SSC systems demonstrated high clinical success, with overall crown retention exceeding 97%. Good marginal adaptation was observed in 98.3% of crowns and was significantly more frequent in the Kids Crown group than in the NuSmile group (<i>p</i> = 0.038). No significant intergroup differences were found for retention, occlusion, proximal contact, gingival index, or oral hygiene status. Parental satisfaction scores were high in both groups, particularly regarding durability and overall satisfaction.</p> Conclusions <p>Both Kids Crown and NuSmile SSC systems showed high clinical success and parental acceptance in pediatric patients treated under general anesthesia. Although marginal adaptation favored Kids Crown, the overall clinical relevance of this difference appears limited.</p> Trial registration <p>The trial was registered retrospectively on May 8, 2025 (ClinicalTrials.gov, NCT07393854).</p>