The effect of gadolinium-DTPA (Gd-DTPA, Schering AG) as a magnetic resonance imaging (MRI) contrast agent was studied in 15 patients with liver tumours. A dose of 0.1 mmol/kg was used. An analysis of the time-course of enhancement, a comparison of four different pulse sequences, and a dose-comparison study were carried out with monitoring of haematological and biochemical parameters before and after injection of Gd-DTPA. Maximum enhancement, that is, increase in signal intensity, was noted on IR1400/400/13 between 10 and 20 min after injection while on SE580/40 and SE580/80 maximum enhancement was noted 30 min after injection. In some cases enhancement was noted up to 120 minutes after injection. SR1000/13f sequences showed very little enhancement. On comparison with contrast-enhanced X-ray computed tomography (CT), enhancement was greater on MRI in seven cases, equal in six and less in two, as assessed subjectively. Additional lesions were shown in one case using Gd-DTPA compared to precontrast enhanced MRI scans. However, no additional lesions were seen on contrast-enhanced MRI scans compared to contrast-enhanced CT scans. Gd-DTPA is capable of enhancing liver tumours on MRI and may have a place in the assessment of the operability of such lesions.