Jatropha curcas has drawn the attention of researchers in recent times as a high potential substrate for production of biodiesel. However, like many other substrates, fuel properties of its biodiesel vary with such factors as growing and climatic conditions. This paper presents experimental results for jatropha methyl ester of Botswana’s semiarid climatic conditions. Physicochemical properties, performance and emissions characteristics of jatropha methyl ester and its blends with petroleum diesel were investigated experimentally. The results showed that viscosity values for all fuels fall within specifications of American Standard Test Methods (ASTM), with a maximum variation of 21% observed between B0 and B100. Cold flow properties of cloud and pour points indicate that jatropha methyl ester and its blends can power the diesel engine without much difficulty in cold weather. The flash points of jatropha methyl ester and its blends were found to be lower than the ASTM specification of a minimum of 130oC, implying that the fuels are highly flammable and need extreme handling precaution during transportation. Biofuels depicted better engine performance when compared to petroleum diesel in terms of brake power, specific fuel consumption (SFC) and brake thermal efficiency (BTE). This is largely attributed to higher combustion efficiency due to extra inbound oxygen. Higher combustion efficiency of biofuels led to reduced production of hydrocarbons (HC), carbon monoxide (CO) and carbon dioxide (CO2) emissions when compared with petroleum diesel. Petroleum diesel was also observed to produce the highest proportion of soot during combustion in the magnitude of approximately 3% per 3ml of fuel.