This article assesses the effects of mobile phone use on the artisanal fishing industry in the Effutu Municipality of Ghana. It contributes to the growing literature on how mobile telephony can help overcome market inefficiencies in developing countries due to imperfect information. The study shows how mobile phone use among fishermen has enhanced the efficiency of input and output markets for artisanal fishing and improved their businesses relations and livelihoods. The ‘before and after’ approach was used, based on interviews with fishermen and other supply chain actors on ways in which fishermen bought inputs and sold fish, and their perceptions of the effects of the mobile phone. The results indicate that market efficiencies improved and price variations reduced as a result of better availability of up‐to‐date information. Use of mobile phones enabled fishermen to improve their incomes, expand their markets, feel more secure at sea, and remain in closer touch with both families and other fishermen.