The research work set out to assess the impact of cargo throughput on port productivity in Warri Port in the pre-concession and postconcession era, spanning 2000 to 2020, with main focus on productivity, measured from annual cargo throughput. Concession arrangement which started in 2006 was a business strategy by the Government to cede management of the Nigerian ports to private companies for more efficient management. The study formulated and tested hypothesis in using moving average of time series analytical tools. Secondary data of annual cargo throughput obtained from the Statistics Department of NPA Warri, were analyzed. The test revealed that cargo throughput and productivity of the port increased in the post-concession period of 2006 to 2020 relative to the pre-concession period of 2000 to 2020, leading to the rejection of the null hypothesis and acceptance of their alternatives. This indicated that the port become more efficient in infrastructural development and operational management due to the concession arrangement. The study recommended curbing insecurity in and around the port to encourage importers' patronage and also dredging the Escravos bar to allow passage for larger vessels to the port. It went further to suggest some areas of further study among which is the one that borders on a comparative analysis of the impact of wet cargo against dry cargo in the operational performance of the Warri port.