Looking to reduce climate change impact and particle emissions, the heavy-duty transport sector is moving towards a growth within technology and infrastructure for use of liquefied natural gas (LNG). This opens an opportunity for the biogas market to grow as well, especially in the form of liquefied biomethane (LBM). However, there is a need to investigate the economic conditions and the possible environmental benefits of using LBM rather than LNG or diesel in heavy transports. This study presents a comparison of well-to-wheel scenarios for production, distribution and use of LBM, LNG and diesel, assessing both environmental and economic aspects in a life cycle perspective. The results show that while LNG can increase the climate change impact compared to diesel by up to 10%, LBM can greatly reduce the environmental impact compared to both LNG and diesel. With a German electricity mix, the climate change impact can be reduced by 45 – 70% compared to diesel with LBM from manure, and by 50 – 75% with LBM from food waste. If digestate is used to replace mineral fertilizer, the impact of LBM can even be less than 0. However, the results vary a lot depending on the type of feedstock, the electricity system and whether the calculations are done according to RED or ISO guidelines. Economically, it can be hard for LBM to compete with LNG, due to relatively high production costs, and some form of economic incentives are likely required.