Background This study aimed to evaluate the work engagement status of registered pediatric nurses and its relationship with personal- and work-related variables in selected hospitals. Personal- and work-related factors generally influence work engagement. However, data on work engagement in pediatric clinical practice are limited. Methods This study employed a cross-sectional design, including 230 registered nurses working in pediatric units in Madinah, Saudi Arabia. A non-probability approach (convenience sampling) was adopted in recruiting the sample. Eight personal- and work-related variables were examined using the Utrecht Work Engagement Scale shortened 9-item version. Results The overall mean scale score was 4.54 (standard deviation = 0.95). The dedication subscale showed the highest mean score (4.84), followed by the absorption (4.48) and vigor subscales (4.29). A higher work engagement score was associated with an older age (H = 17.892; p < 0.001), a non-Saudi nationality (Z = 5.724; p < 0.001), a higher educational level (Z = 3.178; p = 0.001), and a long duration of experience (>10 years) (H = 18.435; p < 0.001). No significant differences were observed between the total scale score according to marital status (p = 0.077), current working unit (p = 0.063), and current working hours (p = 0.067). Conclusions Among registered pediatric nurses, work engagement is relatively high but is average in terms of the vigor component. To our knowledge, this research is the first to explore how work environment affects work engagement among pediatric nurses in Madinah, Saudi Arabia.