Over the past few decades, science has devoted itself more intensively to the development of biofuels with the aim of reducing environmental pollution caused by the burning of fossil fuels. Likewise, the increase in the number of the world's population, rapid industrialization, urbanization, are just some of the factors that cause the growing demand for energy and thus encourage the ever-increasing use of fossil fuels. As fossil fuels are non-renewable sources of energy, researches aimed for fuel that would come exclusively from renewable sources. Biodiesel proved to be a good alternative due to its environmentally friendly nature. It is obtained by catalytic transesterification - the reaction of feedstocks (vegetable oils and animal fats) with an alcohol in the presence of a catalyst. An integral part of fats and oils are triglycerides - esters of glycerol and fatty acids that participate in the transesterification reaction with an alcohol. Therefore, fatty acid alkyl esters (biodiesel) and also alcohol glycerol as a by-product are produced. In this work, biodiesel was synthesized by base – catalyzed transesterification from palm oil as the main feedstock and selected straight-chain alcohols: 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-octanol, in the presence of a base catalyst - potassium hydroxide (KOH), since the application properties of biodiesel depend on the structure of the reactants used in the synthesis. The effects of certain parameters on the synthesis reaction were monitored: reaction time (5, 15, 60 minutes), temperature (60 °C), molar ratio of alcohol and oil (5:1 and 10:1) and mass fraction of catalyst (1 wt.% KOH and 3 wt.% KOH). In addition to the influence of the mentioned parameters, the influence of the molecular weight of alcohol on the reaction conversion was investigated, as well. With regard to the mentioned alcohols in the biodiesel synthesis reaction, fatty acid propyl, butyl, pentyl, hexyl and octyl esters were produced. The obtained results show that the reaction time has very little or no influence on the reaction conversion. Increasing the mass fraction of the catalyst and the molar ratio of alcohol to oil generally leads to a higher reaction conversion. As the molecular weight of the alcohol increases, the polarity of the alcohol decreases, and ultimately of the alkoxide anion, which plays a major role in the base transesterification mechanism. As the polarity of the alkoxide anion decreases, its affinity towards the ester group of triglycerides also decreases, and thus the conversion of the reaction decreases.