Background: Evaluation of physical activity by condition-specific surveys provides more accurate results than generic physical activity questionnaires. The aim of this study was to investigate the reliability and validity of the Kaiser Physical Activity Survey (KPAS) in Turkish pregnant women. Methods: In the translation and cultural adaptation of the KPAS, the 6-phase guidelines recommended in the literature were followed. The study included a total of 151 pregnant women who were assessed using the Turkish version of KPAS, the Pregnancy Physical Activity Questionnaire, and the SenseWear Pro3 Armband. To determine the test–retest reliability, the KPAS was reapplied after 7 days. The psychometric properties of KPAS were analyzed with respect to internal consistency, test–retest reliability, and concurrent validity. Results: Cronbach α coefficient indicating the internal consistency of the Turkish KPAS was found to be .60 to .80, showing moderate reliability. The intraclass correlation coefficient for test–retest reliability was very strong (intraclass correlation coefficient: .96–.98). The total KPAS scores were found to be moderately correlated with the total Pregnancy Physical Activity Questionnaire score and the total energy expenditure value on the SenseWear Pro3 Armband. Conclusions: This study showed that KPAS is a valid and reliable instrument for evaluating physical activity in Turkish pregnant women in different aspects.