The African mosquito Anopheles gambiae is the insect vector responsible for half of worldwide malaria infections. One option for reducing malaria is genetic manipulation of the vector. By creating transgenic mosquitoes incapable of spreading the malaria pathogen, the human-mosquito-human cycle of infection may be interrupted. In order for the engineered Plasmodium-refractory mosquitoes to be effective they need to be able to thrive in nature and to compete successfully with nontransformed conspecifics. Two lines of transgenic An. gambiae were used in this study to evaluate the fitness consequences of transgenesis in this insect. Life table characteristics of two transformed An. gambiae lines were compared to a control line to determine if fitness costs were present. Specific traits measures between transgenic and control mosquitoes were not significantly different, and the transgenic lines had no evidence of position effects.