One amongst the many challenges in energy transition is a switch from conventional fuels supplying the heavy-duty vehicles, used in transportation, agriculture or constructions sectors, to alternative sources of energy. One of the promising fuels that would serve the purpose of decarbonization is the ammonia which is one of the major chemicals produced worldwide. Implementation of ammonia as a fuel in internal combustion engines is possible due to the its characteristics: it could be considered as hydrogen vector whereas it is easier to store and transport than pure hydrogen. Environmental effect of switch from diesel fuel to ammonia in internal combustion engine for heavy-duty vehicles should be assessed in terms of life cycle assessment of the vehicle since typically it is the operation phase which dominates the environmental impact of the vehicle, as shown in the literature, however when utilizing the ammonia as a fuel, the production cycle of the ammonia requires careful consideration – so that environmental benefits in terms of while life cycle of the vehicle are actually achieved. This study focuses on comparison of three ammonia production technologies: ammonia utilizing hydrogen from steam methane reforming, hydrogen from steam methane reforming with carbon capture and storage and hydrogen from electrolysis supplied from PV energy. GaBi software is used to perform the LCA, GaBi Professional Database is the primary choice of data, secondary data are based on literature. The environmental performance is referred through three midpoint indicators from ReCiPe 2016: climate change, fossil depletion, freshwater consumption. It is confirmed that electrolysis is the best choice from the climate change perspective, however its water usage should be considered as it requires around two times more water than ammonia utilizing hydrogen from steam methane reforming.