In recent decades, urban air pollution has increased considerably in Mexico City, leading to harmful effects on the ecosystem. To reduce pollutant emissions, new sustainable technologies have been adopted in the transport sector. To date, no studies have conducted a technoeconomic analysis of the environmental impact of electric vehicles (EVs) in regard to taxis in Mexico. To address this gap in the research, this study aimed to perform a cost-environmental impact assessment of electric taxi introduction in Mexico City using the life-cycle cost (LCC) methodology and the greenhouse gas (GHG) emissions assessment. Furthermore, a sensitivity analysis was performed to identify parameters with the greatest influence on the LCC. The LCC of EVs was found to be larger than that of internal combustion vehicles (ICVs); the acquisition cost was identified as the greatest contributor to the total LCC, followed by the maintenance cost. Worldwide, mixed results have been reported due to differences in the use of local parameters and values. To promote EVs, it is necessary to reduce either acquisition costs or battery costs. The environmental analysis showed that there is only a slight reduction in GHG emissions with electric taxi introduction. Nevertheless, cleaner renewable energy sources must be adopted and considered in order to achieve a much greater reduction and take full advantage of the benefits of EVs.