This paper, Part II of a two part paper, presents a comprehensive correlation aimed to bring out the accurate prediction of the turbine mode operation of centrifugal pumps. This work uses experimental data of wide range of pumps representing the centrifugal pump configurations in terms of specific speed. Based on specific speed and specific diameter an accurate correlation is developed to predict the performances at best efficiency point of the centrifugal pump in its turbine mode operation. The proposed prediction method yields very good results to date compared to previous such attempts. The present method is compared to nine previous methods found in the literature. The comparison results show that the method proposed in this paper is the most accurate. The proposed method can be further complemented and supplemented by more future tests to increase its accuracy. The proposed method is meaningful because it is based on both specific speed and specific diameter. (C) 2016 Elsevier Ltd. All rights reserved.