An experimental study of the TiCo/TiCo+Ti2Co and TiCo/TiCo+TiCo2 phase boundaries has been carried out using high‐temperature x‐ray diffractometry. The results, together with the result of an approximate mp determination, have been used to delineate the TiCo phase field. By combining this information with the results of other work reported in the literature, a complete TiCo phase diagram has been constructed for the first time.