Combined Random Forest and Naive Bayes method can produce better prediction accuracy. This study uses the combined Random Forest and Naive Bayes method to see whether the combined method will always produce better results than the individual method, or not. Based on the result of 280 test cases with Pima Indian diabetes dataset, the combined method only outperformed the accuracy of both the individual Random Forest and Naive Bayes method for 96 times, losing to Random Forest that outperformed the combined method and individual Naive Bayes method for 127 times.