Studies in the field of elasticised woven fabrics made of Co/PBT yarns indicate great potential of PBT use in woven fabrics. Weaving experiments demonstrate that elasticity of Co/PBT fabrics gained after treatment depends not only on woven fabric settings but also on onloom settings. Therefore, it is difficult to predict precisely the degree of shrinkage of the Co/PBT fabric after treatment. Six samples of woven fabrics were produced, three samples with the pretreated core spun Co/PBT weft, each in a different weave. Other three samples were woven with untreated core spun Co/PBT weft, in the same weaves and afterwards the samples were treated. The results indicated big differences between samples with pre-treated Co/PBT yarns in weft direction and samples treated after weaving.