Surgical latex gloves and a natural rubber latex (NRL) catheter were evaluated for biocompatibility by cell culture methods and Type I allergic reactions in operating room personnel using latex gloves. The prevalence of relevant immediate allergy to NRL was 5.2% when using eluates made from different latex gloves as allergens and the skin-prick test methodology. The reliability of a questionnaire in detecting the sensitized persons was limited. Weak positive skin test reactions to surgical latex glove eluates were found to be unreliable as compared with challenging with the corresponding glove. Latex gloves exhibited more toxicity in cell culture than non latex gloves, but, inversely, the toxic catheter gave weak positive skin-prick test reaction in only one sensitized person, confirming that the allergenicity and toxicity of natural rubber products do not refer to the same properties of the products. Catheters exhibiting toxicity in cell culture have earlier been found to cause significant clinical symptoms in operated patients, but in the case of surgical gloves this relationship is not clear. One glove brand with a low content of known sensitizing rubber chemicals caused clear toxicity in cell culture but was well tolerated by the hospital personnel.