The American Academy of Pediatrics (AAP) recommends screening children for developmental delay and autism. Studies of current screening practice to date have been limited in scope and primarily focused on small, local samples. This study is designed to determine compliance with AAP screening recommendations: (1) developmental screening at 9, 18, and 24 or 30 months; (2) screening when concerns are raised at a surveillance visit; and (3) autism screening at 18 and 24 months and to examine pediatrician and practice characteristics associated with compliance. Pediatricians from 6 states completed a 38-item web-based questionnaire (N = 406) regarding compliance with recommendations, screening implementation, changes in screening practice since the publication of guidelines, and pediatrician and practice demographics. Overall, 17.8% of pediatricians were compliant with all 3 screening recommendations. A total of 41.6% of pediatricians screened for development at the 9-month visit, 58% at the 18-month visit, and 52% at the 24- or 30-month visit. A total of 59.8% of physicians screened for autism at the 18-month visit and 50.2% at 24-month visit. As compared with 5 years ago, 44.8% of pediatricians currently screen for development more often and 72.2% screen for autism more often. Pediatricians with 10%-50% of patients of non-White race/ethnicity in their practice were significantly less likely to screen for developmental delay than pediatricians with more than 50% of patients (odds ratio [OR] = 0.30; 95% confidence interval [CI] = 0.13, 0.69; p = 0.004). Similarly, pediatricians with 10%-30% of Medicaid-insured patients were less likely to screen for developmental delay than pediatricians with more than 30% of patients (OR = 0.45; 95% CI = 0.25, 0.80; p = 0.0007). In contrast, pediatricians with 10%-30% of Medicaid-insured patients were significantly more likely to screen patients for autism than pediatricians with more than 30% of patients (OR = 2.46; 95% CI = 1.38, 4.40; p = 0.0002). Increasing numbers of pediatricians are screening children for developmental delays and autism. Economically disadvantaged children are significantly more likely to be screened for developmental delay but less likely to be screened for autism than do less disadvantaged children.