Hole and electron transport has been studied by the time-of-flight technique on disubstituted diaryldiacetylene layers prepared by the vacuum deposition method. Basic transport characteristics and their dependence on the electric field, temperature and chemical structure of molecules ale determined. The data are fit well into a correlated disorder model. Results of an semiempirical quantum-chemistry calculation (PM3, ZINDO/S) on diaryldiacetylene molecules are in agreement with the experimental data.