The purpose of this study is to determine whether the use of the Goretex Pantaloon cast liner for children's spica casts reduces urine excoriation of the skin under the cast and reduces the incidence of unplanned cast changes necessitated by cast soilage. Between 1988 and 1993, 72 consecutive children who had 147 hip spica casts applied were followed. The first 36 patients had 77 spica casts applied without the Goretex Pantaloon, and the last 36 patients had 70 spica casts with a Goretex liner. In the group of patients without Goretex, 22% of casts were associated with urine excoriation of the skin compared to 1.4% in the group of patients who had a Goretex liner applied. This was statistically significant (p = 0.0005). The incidence of unnecessary cast changes due to soiling of the cast was 14% in the non-Goretex group compared to 2.9% in the Goretex group (p = 0.05). The use of the Goretex liner in our series resulted in a savings of $38 per cast including the cost of the liners ($75). The Goretex Pantaloon cast liner used for children's spica casts prevents urine excoriation of the skin and is cost effective.