The publication describes the properties of isopropyl alcohol and is exploring the possibility of its use as an additive to diesel fuel. Experimental results from operation of the diesel engine with 15% isopropyl alcohol are shown. The advantages of using a 15%- mixture of isopropyl alcohol and standard diesel fuel are presented here. The main physicochemical parameters of the isopropyl alcohol are also shown as well as the specification of the used diesel fuel. The specifications of the test engine are given here in detail. The experimental results are presented in both tabular and graphical form. The main economical parameters are show as a function of the load characteristics. Graphical functions proving the smoke density reduction as a function of the load characteristics, air-fuel ratio and multi- parameter characteristics are also presented. The smoke reduction is observed in exhaust gas of the diesel engine.