Aims: A standardized antenatal scoring system is not available in order to detect high-risk pregnancies at primary health care units in Turkey. The authors aimed to evaluate the applicability of the "Knox scoring system" in Turkey. Materials and Methods: One hundred and twenty-nine pregnant women were included in study. They were assessed upon admission and then the same women were reassessed at the onset of labor by Knox scoring system. Results: The Knox scoring system identified 65 pregnant women (50.4%) as high-risk upon admission while 22 pregnant women (17.1%) as high-risk at the onset of labor. Twelve pregnant women (9.3%) (one case of perinatal death and 11 cases of perinatal morbidity) had poor perinatal outcomes during the study period. The Knox scoring form administered upon admission yielded 58% sensitivity, 50% specificity, and 10% positive predictive value, while 91% sensitivity, 90% specificity, and 50% positive predictive value at the onset of labor. The diagnostic value of the Knox scoring system for determining high-risk pregnancies was not found statistically significant regarding admission (ROC value: 0.655; p>0.05), while statistically significant regarding the onset of labor (ROC value: 0.946; p < 0.05). Conclusions: The use of the Knox scoring system for determining high-risk pregnancies seems to be effective at the onset of labor.