The relative abundance of mosquito larvae in some habitats in Port Harcourt city was studied. Water samples from five locations were collected and physico-chemical parameters of the water were evaluated in-situ and ex-situ. The Larvae populations were assessed for a period of five days. The results showed that the average pH, temperature, electrical conductivity, Total Dissolved Solid, Salinity recorded for samples from Aggrey road were 7.80±0.54, 27.27±0.48, 437.70±330.37, 240.75±170.07, 234.75±171.99 respectively; Amadi-Ama were.73±0.48, 25.69±0.42, 303.8±138.39, 154.70±71.25 and 151.75±68.76 respectively; Diobu were 7.78±0.53, 29.81±0.49, 874.70±361.3, 442.55±185.16 and 440.95±188.97 respectively; Elekahia were 7.65±0.39, 27.13±0.19, 805.95±297.23, 396.15±148.89 and 397.5±149.88 while Rumukalagbor were 7.53±0.28, 29.26±1.810, 676.75±281.79, 347.40±119.24 and 343.55±127.21 respectively. Data analysis showed that the pH value of the five locations were significantly different at (p<0.05) while the p-value for Temperature, Electrical conductivity, Total Dissolved Solid and Salinity shows no significant differences. The larvae population in the studied areas showed that Diobu recorded 466 (43.4%), Amadi-Ama had 314 (29.3%), Elekahia had 220 (20.5%), while Aggrey road had (1.86%). the result showed that Diobu axis of the studied areas had water habitats that encouraged the hatch ability of eggs. Also, two genera were identified, Anopheles mosquito larvae 725 (67.5) and Culex mosquito larvae 349 (32.5). There was a significant difference in the two species of mosquitoes at P<0.05. This suggests that the residents within the study area are at risk of mosquitoes-borne diseases. The study recommends strict enforcement of proper waste management, cleaning of drainages, quick repair and maintenances of debilitated drainages and health enlightenment campaigns within the study area which will reduce the breeding of these mosquitoes and reduce the transmission risk.