This systematic literature review (SLR) aims to synthesise the empirical evidence on the usability and impact evaluations of mobile phone-based agricultural market information services (AMIS) on rural small-scale farmers (SSFs) in developing countries. The results showed that, while providing access to agricultural market information (AgriMI) e.g., on best market prices and value-added services through mobile phones-based AMIS to allow rural SSFs to acquire it, enabling them to sell their agricultural commodities at higher prices has accounted for why numerous mobile phones-based AMIS have emerged in some developing countries, there have been general differences in the usability and impact evaluations of such services on the rural SSFs e.g., most have been evaluated on self-reported data only. With these results, future AMIS providers should consider rigorous usability and impact evaluations on actual data usage patterns of such services on a daily basis to determine whether, and how much such services have impacted on the rural SSFs’ sale prices, volumes, and incomes in developing countries.