Fuel adulteration is becoming a widespread problem in South Asian countries, some forms of which are responsible for deterioration in performance and increase in emissions of spark ignition (SI) engines. A common form of adulteration is to blend gasoline with kerosene which is prevalent because of financial benefit resulting from the price difference between the two fuels. In addition to rendering the fuel more knock prone, based on previous studies it can be surmised that gasoline adulteration with kerosene would increase hydrocarbon (HC), particulate matter (PM) and polycyclic aromatic hydrocarbon (PAH) emissions from SI engines. However, detailed information about the emission effects with the extent of adulterant in the fuel is lacking. This paper elaborates on the effects of kerosene adulteration starting from change in the properties of the gasoline, including volatility and enthalpy of vaporization, to combustion characteristics of gasoline-kerosene blends in an SI engine. It also presents the HC and PM emission effects of such blends. The results quantify an increase in these harmful emissions with the increase in kerosene in the blend.