This study assessed parents’ knowledge about space maintainers as an interceptive strategy after premature loss of primary teeth. Methods and Material: A cross-sectional questionnaire-based descriptive study was conducted on a sample of 600 parents; 456 (76%) were females, and 144 (24%) were males, recruited from an outpatient dental clinic at Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. The questionnaire consisted of two sections; the first section collected sociodemographic data of participants, and the second section gathered parental knowledge of space maintainers. The research ethics committee granted ethical approval, and informed consent was obtained before participation. Results: 600 parents participated in this study. The total mean knowledge score regarding space maintainers was 7.97 ± 3.38. The mean knowledge score was 7.06 ± 2.99 for male parents and 8.26 ± 3.45 for female parents. The difference in the mean knowledge score between female and male parents was statistically significant (p < 0.001). Additionally, there was a statistically significant difference in the knowledge score and parents’ age groups, with parents having the highest knowledge in the 30–40 age group (p = 0.0197). There was a positive correlation between knowledge scores and the number of children. Parents with one child showed less knowledge than those with two to four children (p = 0.0121). Conclusions: Participants’ knowledge regarding space maintainers was 49.8%, which is considered inadequate. It was deemed essential to increase knowledge among parents about space maintainers as an interceptive approach after premature loss of primary teeth.