The characteristic feature of small cell lung cancer carcinoma (SCLC) is the aberrant expression and abundant presentation of fucosyl-GM1 ganglioside (FucGM1). In the present study we searched for the presence of anti-FucGM1 ganglioside, as well as anti-GM1, GM2 and GD3 ganglioside autoantibodies in the sera of patients with SCLC and as a control, in sera of patients with renal cell cancer (RC) and healthy blood donors. The autoantibodies against FucGM1 were present at low titer in only three of 36 SCLC patients, and with similar titer in two of 36 RC patients and four of 36 healthy controls. Likewise, the autoantibodies against GM2 and GM3 gangliosides were found only sporadically and with the same titer and frequency in cancer patients as in healthy persons. Anti-GD3 autoantibodies could not be detected in any of the screened sera.