Over the last decade, governments throughout eastern and southern Africa have increasingly used strategic reserves and/or marketing boards to influence grain market outcomes, yet little is known about how these activities are affecting grain markets. This article estimates the effects of the Food Reserve Agency (FRA) on maize market prices in production and consumption regions in Zambia using a vector autoregression model and monthly data from July 1996 through December 2008. In recent years, FRA has become the dominant buyer of smallholder maize in Zambia. Simulations show that FRA activities stabilized market prices throughout the July 1996–December 2008 study period and raised mean prices between July 2003 and December 2008 by 17–19%. The price raising effects of FRA policies have assisted surplus maize producers but adversely affected net buyers of maize in Zambia, namely urban consumers and the majority of the rural poor. The increase in maize price stability is unlikely to have had substantial welfare effects on poor households. In contrast, relatively wealthy producers are likely to have benefited from the higher average and more stable maize prices resulting from FRA policies.