A cross-linkable semiconducting polyfluorene was synthesised and used, in the cross-linked, insoluble form, in the fabrication of field-effect transistors, FETs. This photopatternable polymer derives from the well known poly(9, 9-dioctylfluorene-alt-bithiophene), F8T2, which is one of the most studied semiconductors for FETs. We find that FETs using this cross-linked polyfluorene semiconductor show p-type behaviour with mobility 8.3 x 10 x 5 cm(2)/V s. Although this value is one order of magnitude smaller than that found for similarly prepared F8T2-based FETs (6.8 x 10 x 4 cm(2)/V s), and which we mainly attribute to disorder, the use of this type of polymer opens new perspectives in terms of device fabrication. (C) 2008 Elsevier B.V. All rights reserved.