Objective: To inform professionals pioneering developmental-behavioral pediatrics (DBP) services in low- and middle-income countries (LMICs), we aimed to examine referral trends in 2 pioneering DBP centers at different locations in Turkey and to ascertain whether the official establishment of DBP as a subspecialty affected these trends. Method: This longitudinal observational study included all children referred to Ankara (AUDPD) and Inonu (IUDPD) Universities' Developmental Pediatrics Divisions between 2010 and 2018. We examined the sources of referrals and the independent effects of time and the establishment of DBP as a subspecialty on referral volume using Negative Binomial Regression (NBR) models. Results: Of 8,051 children, most were boys (58%) and under 24 months of age (72%). Most referrals were from the pediatric and pediatric surgery department clinics (85%); less than 1% were from child and adolescent psychiatry, and none were from family physicians. The NBR models showed that yearly, the referral volume increased significantly, 1.18-fold (95% confidence interval [CI] = 1.09-1.28) and 1.48-fold (95% CI = 1.20-1.82) for AUDPD and IUDPD, respectively. Compared with the trend of referrals before, the trend after the establishment of DBP as a subspecialty increased significantly at AUDPD, but not IUDPD. Conclusion: The increase in referrals to DBP over time is encouraging to professionals working to advance DBP services and training in LMICs even if DBP is not officially established as a subspecialty. Additional efforts may be needed to improve recognition and use of DBP services by community physicians and allied disciplines that provide services to children.