The presence of the small rice mills in the Office du Niger zone has changed the structure of the rice subsector, helping to reduce concentration and changing marketing options of both farmers and retailers. Current proposals call for major initiative to liberalize the rice market further and to shift the principal role of the O.N. toward provision of water and extension. In this context, it is extremely important to investigate the role of small mills in the subsector, their relative costs, and the segments of the market they serve. Budgeting techniques were used to analyze milling cost data. Price data were used to calculate both correlation coefficients and spatial marketing margins. The analyses of correlation and calculation of spatial margins provided indications on the performance of rice subsector in the Office du Niger zone. The financial analyses revealed that the own-mill-sell or buy-mill-sell activity is far more profitable than the custom milling. Moreover, the analyses suggests that most of the millers sampled would be willing to buy paddy at a higher price than the O.N. support price of CFAF 70 per kg.