The paper quantified the yield responses of maize, millet and sorghum in Nigeria using error correction model. The analysis was carried out using a time series data covering 1966-2008. LR-test statistic showed that there was cointegrating vector implying a unique long-run equilibrium relationship with the assumption of linear deterministic trend in the data. The error correction model results indicated that maize, millet, and sorghum yield were not significantly dependent on the prices of maize, millet, and sorghum in the short-run with the exception of millet yield which was dependent on own price. In the long-run, maize yield was statistically dependent on the prices of millet and sorghum. The paper concluded that maize supply was influenced by market signals (prices) and hence small incremental changes in millet and sorghum prices have significant impact on national maize supply level. It is recommended that millet and sorghum price stabilization policy will go a long way in increasing maize production. This will have a consequential effect of increasing the welfare of maize farmers.