Fifty-six tetraplegic patients with motor complete lesions (Frankel A and B) underwent spirometric measurements more than 6 months after injury. The results were evaluated according to the level of transection of the cervical cord. A pronounced restrictive respiratory dysfunction was demonstrated in all patients. The expiratory reserve volume (ERV) was zero or markedly reduced in patients at all lesion levels. Systematic increases in both ERV and vital capacity (VC) were found with lower lesion level. The inspiratory capacity (IC) was reduced at all injury levels, but there were no systematic differences in IC between injury levels C4-C8. The total lung capacity (TLC) was reduced and the ratio residual volume/total lung capacity (RV/TLC) was increased in patients at all injury levels. The lung function of patients tested > 12 months after injury was not significantly different from the function in those tested 6-12 months after injury. A respiratory rehabilitation programme for tetraplegic patients should take into account the fact that the respiratory function, especially the forced expiration, is dependent upon injury level.