The study assessed the portrsquos security and performance in Port Harcourt Seaports Complex, Port Harcourt, Rivers State, Nigeria. The study made use of 291 copies of structured questionnaire administered to the staff of the Nigeria Ports Authority (NPA), BUA Ports and Terminals Ltd, Port Harcourt and terminal operators/stevedores and Dock workers in Port Harcourt Port Complex using a simple random sampling technique. Descriptive statistics in form of frequency and percentages were used to analyze the data. Multiple regression analysis was used to determine the relationship between port security and port performance. Statistical Package of Social Sciences (SPSS) version 20.0 was used for the data analysis. Findings revealed that among the security facilities, fire alarm system, gun boat, wall mounted motion sensor biometric time attendance and security alarms were adequately available while security gadgets like spy camera face cap, portable hand held security, belt buckle spy camera, biro button, and wristwatch camera were adequately available at the Port Harcourt Seaport Complex. Types of port insecurity included burglary and armed robbery (27.0%) smuggling activities (28.0%), sea piracy (8.0%) and touting (93%). Cargo throughput was highest 2011 (12.1%) and least in 2015 (4.6%) while the ship turnaround time for Port Harcourt Seaport was highest in 2011 (12.46 days) and the least was recorded in 2009 (8.03 days). Cargo throughput, ship turnaround time, berth occupancy rate and tonnage per ship jointly contributed 32.4% to port security in Port Harcourt Port Complex though no significant influence of port security on port performance (t=0.757 p=0.483). The study therefore recommended among others that the International ship and port facility security code (ISPS) should be adequately implemented more both at the terminals and jetties