Seasonal analysis of the structure, conduct, and performance (SCP) of markets for staple crops has received relatively little attention in food policy analysis yet it has important implications for food and nutrition security. This study employs a mixed methods approach to analyse the SCP of maize markets in Malawi in the 2018/19 main harvest and lean seasons. We interviewed 749 traders from 74 markets across 8 districts, held 28 focus group discussions (FGD) with a total of 480 farmers and analysed daily and weekly price data from 13 regional markets. The structure of maize markets was explored by examining marketing channels, barriers to entry and the competitiveness of different tiers of the marketing chain. Inequality in sales revenues, switches in trader types between seasons, quality and weights standardisation, and the behaviour of traders were used to examine market conduct.