Clinical trials on altered fractionation radiotherapy (RT) regimens currently play a significant role in lung cancer, due to the importance of local control and to the disappointing therapeutic results in this disease. In non-small-cell lung cancer (NSCLC) two strategies are being actively investigated: hyperfractionation with a "curative" aim, and hypofractionation with a palliative aim; in small-cell lung cancer (SCLC) altered fractionation seems to play a minor role at this moment. In this review paper the results of reported randomised trials are summarised and discussed. Conclusions may indicate that through hyperfractionation, particularly if accelerated, clinical outcome of non-metastatic NSCLC patients can be improved; data are however not sufficiently mature to advise its use outside controlled clinical trials. In the palliative setting, hypofractionation should be considered standard treatment.