In some cultures inheritance customs results in land fragmentation such that over time operating farms become composed of a collection of spatially dispersed fields rather than a contiguous land unit. This study was conducted to determine the impact of land fragmentation as measured by average field size on the average cost of producing wheat in the rain-fed region of Northern Jordan. Primary data were collected from farmers in the region. Generalized Least Squares was used to estimate the average variable cost of producing wheat. It was determined that the average variable cost of producing wheat is a decreasing function of field size. Land fragmentation increases production costs. Continued land fragmentation will lead to decreasing efficiency and is problematic when it results in small fields.