Phenomenal industrial activities worldwide in the last couple of centuries have resulted in indiscriminate use of conventional energy resources and environmental degradation. The consumption of petroleum-derived fuels has increased exponentially due to enhanced mobility and also caused serious threat to earth's eco-system. The need to explore variety of alternative fuels in transportation sector has been the subject of research all over the world. In this context, alcohols like butanol and isopropyl alcohol seem to present a viable option for potential application in diesel engines. In the present investigation, 5%, 10%, 15%, 20% (v/v) blends of isopropyl alcohol and diesel was prepared. The various blends were found to be homogenous and stable. The exhaustive engine trials were carried out on a single-cylinder unmodified diesel engine. The results suggest significant reduction in emission of oxides of nitrogen (NOx for various blends as compared to baseline data of diesel. At no load condition, NOx emissions are nearly same for all the test fuels. However, at peak load 5.8% reduction in NOx emissions was observed with 5% blend and 13.4% reduction was observed with 20% blend. The brake thermal efficiency increased slightly for 15% and 20% blend. At lower loads, an increase in BSFC was observed. However, at peak loads, variation in BSFC was insignificant. The UBHC emissions were higher and CO₂ was found to decrease with increased percentage of isopropyl alcohol. At peak load, CO emission increased for all the blends and 20% blend showed lower smoke opacity at peak load.