This paper examines how the government of Zimbabwe conceptualized and has implemented the carbon tax legislation that was designed to combat greenhouse gas emissions across the country. The tax was based on the application of the ‘polluter pays’ principle. The paper observes that in the early stages of its implementation, the tax was collected as a separate amount of money from motorists. However, with passage of time, the tax was incorporated into the fuel price, and for that reason, could therefore have lost its deterrence effect. Moreover, the tax was calculated based on the engine capacity and not the age of the vehicle, which many motorists found to be unrealistic. There was also no evidence of the tax being supported by scientific measurements of emission, nor a clear emission-reduction strategy. These shortcomings were essentially a consequence of a combination of technical, financial and human constraints. Without a clearly spelt out overarching environmental goal, the carbon tax has failed to achieve the objectives for which it was set up. The paper concludes that the environmental tax needs to be better targeted, and should take into account relevant scientific and institutional issues.