This study was conducted to evaluate the susceptibility and efficacy of three insecticidal treated bednets; Olyset®, PermaNet2.0® and MAGNet® collected from the different health facilities, against Anopheles mosquitoes under laboratory conditions. PermaNet3.0 was used as a positive control. Larval collections were carried out and reared at the insectary of National Arbovirus and Vector Research Centre, Enugu State. Anopheles Kisumu mosquitoes were used as the standard control in the cone bioassay test. The bioassay showed that the wild An. gambiae s.l. and An. gambiae Kisumu strains were susceptible (100% mortality) to the PermaNet3.0® used as positive control while the wild-caught Anopheles were resistant to the mono-treated ITNs. The mortality effect of the net brands showed that the brands have a statistically significant effect on the mosquito mortality after 24 hours F (2, 18) = 14.32, p < .001), while the sides of the net did not have a statistically significant effect on the mosquito mortality (F (3, 18) = 1.67, p = .209). This study also suggests the need to develop and adopt routine monitoring of the ITNs at the health facilities, as it will inform the replacement of ineffective nets. However, a mass campaign of PBO nets is necessary for the state to achieve and maintain the universal coverage of ITNs.