BACKGROUND/AIMS: The aim of this methodological-descriptive study was to assess the validity and reliability of the "Behaviors of Transition to Complementary Feeding Scale (BTCF-S). MATERIALS AND METHODS: This study was designed as methodological-descriptive one. The sample of this study consisted of 370 mothers with 6-24-month-old babies. The data were obtained using the Parent's Information Form and BTCF-S. RESULTS: The Cronbach's alpha values for this scale and its five subscales were 0.95, 0.95, 0.83, 0.85, 0.75 and 0.85, respectively. Item-total correlations for this scale varied between 0.30 and 0.83 (p<0.001). The Indices of Model Fit used in this study were as follows: the root mean square error of approximation: 0.073, the goodness-of-fit-index: 0.91 and the comparative fit index: 0.90. In the construct validity testing, the Kaiser-Meyer-Olkin value was 0.93 and Bartlett's sphericity test was 6,923.86 (p<0.001). The results of the factor analysis indicated a scale with 28 items, and five factors, where R2=64.56%. The total Cronbach's alpha value for this scale is 0.95. CONCLUSION: According to our results, it was shown that this scale is a valid and reliable instrument which can be used to detect the behaviors of transition to complementary feeding among 6-24-month-old babies of Turkish mothers. The BTCF-S is a convenient tool for professionals in managing and preventing behavioral problems in the transition to complementary feeding.