Between June 1987 and July 1989 laser angioplasty, and between July 1989 and December 1991 rotation angioplasty was used as the method of choice for the recanalisation of chronic (minimal duration 3 months) arterial occlusions in the femoro-popliteal region. The technical success rate and final results following supplementary balloon dilatation were identical and there was no significant difference between the two groups (laser 87%, rotation 87.7%). For long occlusions (more than 150 mm), the success rate for rotation angioplasty was 60% and significantly higher than for laser angioplasty at 40%. Complication rates for rotation angioplasty were 24.3%, higher than laser angioplasty with 20.3%. This was due to the higher incidence of emboli of 12.1% compared with the laser technique of 7.3%. Cumulative patency rates after two years showed no significant difference (uncorrelated/correlated: laser 53.4%/67.8%; rotation 56.6%/67.5%). Using lytic and aspiration techniques, the higher incidence of embolisation during rotation angioplasty had no adverse effect on final outcome. If both methods are available, it is advisable to treat long occlusions by rotation angioplasty because of the high immediate success rate, whereas short occlusions are best dealt by laser angioplasty because of the lower incidence of embolisation.