Recently the use of mobile phones has been a widespread phenomenon. Various services have been provided by mobile phones which delivers opportunities to reduce costly and incomplete information dissemination in the agricultural sector and ensure efficient functioning of markets. But in order to successfully use mobile phones for the optimal development of agricultural markets, understanding the determinants of mobile phone usage in marketing agricultural products based on UTAUT model, its uses and perceived benefits are invaluable. This study will apply a mixed method approach utilizing questionnaire and focus group discussion. Data will be collected from small scale orange farmers in Muheza, Tanzania who will be randomly selected. The collected data will be analysed using structural equation modelling and content analysis techniques. This study is important as the results will provide insights on the determinants of mobile phone usage of orange farmers in relation to the marketing of agricultural products, and the benefits obtained by these farmers, which will help agricultural stakeholders to come up with strategies to help farmers make better use of mobile phone to enhance their market participation.