The autism intervention literature focuses heavily on the concept of evidence-based practice, with less consideration of the acceptability, feasibility, and contextual alignment of interventions in practice. A survey of 130 special educators was conducted to quantify this "social validity" of evidence-based practices and analyze its relationship with knowledge level and frequency of use. Results indicate that knowledge, use, and social validity are tightly-connected and rank the highest for modeling, reinforcement, prompting, and visual supports. Regression analysis suggests that greater knowledge, higher perceived social validity, and a caseload including more students with autism predicts more frequent use of a practice. The results support the vital role that social validity plays in teachers' implementation, with implications for both research and practice.