Rapid water infiltration in unlined canals, reservoirs, and the inflow end of furrows relative to outflow ends result in excessive seepage losses and reduced furrow irrigation application uniformity. This study evaluated the use of cross-linked, anionic, polyacrylamide hydrogel (XPAM), a water absorbing, swellable polymer solid, for reducing infiltration and seepage losses though soil. Experiment 1 and 2 measured the influence of soil treatments on seepage rate in soil columns under constant-head conditions: Exp. 1 treated five soils with 0, 2.5, 5, and 10 g kg^-1 XPAM; and Exp. 2 applied combined XPAM (0 to 5 g kg^-1) and NaCl (0 to 5.1 g kg^-1) treatments to a silt loam soil, and separately tested the effect of XPAM granule-size and treated soil layer thickness on seepage rate. In Exp. 3 a mini-flume was used to determine how a 5-mm-thick, XPAM-treated (0 to 5 g kg^-1) soil layer at the inflow end of the “mini-furrow” influenced water distribution. The 21-h seepage rate of all soils except the loamy sand decreased curvilinearly with increasing XPAM rate, with maximum reductions for 5 and 10 g kg^-1 XPAM rates of 87 to 94%, relative to controls. The <300-μm-diam. XPAM granules were significantly more effective than the coarser-grained XPAM for reducing seepage, and reducing the thickness of the treated soil layer from 71 to 24 mm had no significant effect on the seepage reduction obtained with XPAM. The 5 g kg^-1 XPAM treatment applied to inflow-end mini-flume soils significantly decreased the “furrow-stream” advance period and reversed the infiltration patterns observed in mini-flumes, relative to controls. These XPAM treatments could potentially be used to increase the uniformity of furrow water applications and reduce seepage from unlined irrigation ponds and canals.