The description of Lyme's disease (LD) in 3 stages (like syphilis), has now become classical. 29 cases of LD, between June 1981 and November 1986, have been recorded at the Hospital in Orleans. The first twelve patients that were clinically diagnosed before the serology was introduced in France, have been recalled in order to search for possible late forms and assay their antibody level of anti-Borrelia burgdorferi. The preponderance of neurological forms (22 cases) and the scarcity of peripheral and/or arthralgic arthritis (8 cases) are emphasized by this study. Radiculalgias (18 cases in 22 meningo-radiculitis), especially in the lower extremities (14 cases), required hospitalization in rheumatology in 21 instances. Spinal algias (16 cases), were only isolated, at the time of hospitalization, in one case. The intense and nocturnal nature of the radiculalgias and spinal algias was noted in 17 of 18 cases, and 16 of 16 cases, respectively. Two atrio-ventricular blocks required hospitalization in cardiology. The long-term follow-up (3 to 5 years) of 12 patients revealed only 2 cases of severe asthenia and swelling at the puncture site in one case. There were no entesopathies nor chronic arthritis. The search for anti-Borrelia burgdorferi antibodies in the serum, was positive 24 times in 28. In the 4 cases where the serology was negative, the samplings were taken after a follow-up of more than three years in 3 instances.(ABSTRACT TRUNCATED AT 250 WORDS)