Clay pot method is one of the most efficient traditional systems of irrigation known and is well suited for small farmers in many areas of the world. Pot irrigation system consists of unglazed clay pots; each has many micropores in its wall. The microporous wall guides water seepage from it in the direction where suction pressure develops. When the clay pot buried in the soil, filled with water and crops planted adjacent to it, the pot effects sub-surface irrigation as water seeps out of it due to suction force which attracts water molecules to the plant roots. Field experiments were conducted to quantify the effect of pot volume on water use efficiency and surface wetting edge by comparing the performance of large pots to that of smaller ones. Two types of pot irrigation systems, the first type consists of pots with large volume "PIS1" and the second type consists of pots with small volume "PIS2", were prepared in a clay loam soil by using three crops, namely, tomato, beans, and cucumber. Results showed that water use efficiency when applying "PIS1" was greater than that of "PIS2" for all crops used in the experiments. The crop yield under "PIS1" is higher than that of "PIS2" but it requires much more water for all crops. "PIS2" is a water saving system compared to "PIS1". A positives and significant correlations were found between surface wetting edge and time of seepage opportunity with R2 of 0.96 and 0.93 for large and small clay pots respectively. Results indicate that it is possible to use clay pots with various volumes to consist pot irrigation systems, considering that using pots with small volume leads to decrease water use efficiency and surface wetting edge.