The physical-chemical conditions, phytoplankton diversity and zooplankton diversity of the lower Kafue river were studied in January, 2020. The study was aimed at assessing the physical-chemical conditions of the lower part of the Kafue river and determine the phytoplankton diversity and zooplankton diversity in the lower Kafue River. The study sites that were sampled were Muyanganas at Rub Road Bridge Kafue Fisheries Limited and Kasaka Fisheries Training Centre. Kafue Fisheries Limited is an aquaculture habitat while Muyanganas and Kasaka Fisheries Training Centre are non-aquaculture areas. Water samples were collected using a filtering water sampler. Collected water samples were preserved in 1000 mL plastic bottle by adding 5 mL of 4% formalin concentration. The phytoplanktons were counted using a PX Biological microscope. The plankton species were identified to genus level. Water samples collected from each study site were analysed in order to determine Temperature, pH and Dissolved Oxygen (DO) levels. These parameters were determined using an automated pH meter. The results of regression analysis showed that there was a significant regression of phytoplankton diversity on zooplankton diversity in the lower Kafue river (p = 0.02). However, there was no significant difference (p=0.7451) among the physical-chemical parameters within the study area. The results obtained implied that aquaculture has an impact on both phytoplankton and zooplankton diversity in the lower part of the Kafue river.