Four minor oil discoveries have been made in West Lithuania in recent years. Studies of the oil composition show that its physical and chemical properties (density, viscosity, petrol content, etc.) and the group composition of hydrocarbons (content of saturated and aromatic hydrocarbons, tars and asphaltenes) mainly depend on the formation conditions and distances of migration between the kitchen and accumulation areas. According to the distribution patterns of n-alkanes and isoprenoids, the examined oils are comparable and generated from sapropel organic matter. There are certain differences in biomarker and carbon isotope data, indicating oil generation from different source rocks containing organic matter of different catagenesis.