This study adopted Randomized Control Trial to examine the impact of seed voucher system on farming households’ welfare in Nigeria using cross-sectional data of 600 rice farmers randomly selected from the three major rice ecologies of Nigeria. The WALD estimate reveals that the use of seed voucher increased household Per Capita Expenditure (PCE) by N14705.91. While the result of the Local Average Treatment Effect (LATE), shows a positive and significant impact of N7928.15 on PCE. Therefore, the use of seed voucher to grant farmers assess to certified improved rice seed can generate improvement in farmers’ welfare if strongly pursue.