Three wheat lines, including two spring growth habit landraces from Iran and one winter wheat line, were evaluated for their root volume. Treatments were two pot sizes, 10 cm and 23 cm diameter, and two soil types, washed sand and a mix (v/v) of 1/3 peat moss and 2/3 loam topsoil. Six plants in separate pots of each wheat line for each treatment were arranged in a completely randomized design in a greenhouse with controlled uniform watering, fertilization, light and temperature. The plants were harvested 21 days after heading; shoots were separated from the roots at the crown, the roots were washed, and both shoots and roots were stored at 4°C. Root volume was determined using the Win-RhizoŽ computer software. Iran #14 consistently developed less root volume than Iran #49 and P99608C1. Root volumes were largest for all wheat lines in the 23 cm pots. Although differences among lines were significant in 23 cm pots and the peat-topsoil mix, root tips and fine roots, especially of Iran #14, were lost during washing.