This study attempts to explain the variation in aggregate crop acreage in Argentina in the period 1960-97. It improves on previous studies by incorporating an expected yield variable and input price variables, extending the period of analysis, and attempting an aggregate crop acreage supply-response, of six crops. A single equation model is developed and the naive, moving average and simple weighted average price expectation mechanisms-are examined. Results show that a moving average specification of price expectation accounts better for the data.