Flexible thin-film solar cells on single glass fibers or glass fiber fabrics are in focus of interest, for example as power sources integrated into smart textiles. The high temperature stability of the glass fiber material allows for using this material as substrate for laser crystallized multicrystalline silicon thin-film solar cells. With this solar cell type we achieved an efficiency of 7.8% on conventional glass substrates. In this paper we demonstrate the preparation of multi¬crystalline silicon layers on flexible glass fiber substrates for thin-film solar cells. First the polymer which usually covers the fabric is removed and replaced by a high-temperature paint. Then an amorphous silicon layer is deposited and afterwards crystallized by laser scanning. The flexibility of the glass fibers is preserved during and after these process steps. The grain size of the resulting multicrystalline silicon layer is in the range of 50-1000 µm. A first layer system on the fabric shows photovoltaic properties.