In this study, the association between natural rubber latex (NRL) sensitization and work ability index (WAI) among health care workers was investigated. Furthermore, the diagnostic sensitivity and specificity of a postal questionnaire as a screening device of NRL allergy was evaluated. The study population consisted of 32 female health care workers with an occupational latex allergy, and 51 control subjects who were individually matched for age and occupation. A self-administered two-part questionnaire, including seven items of a work ability index (WAI), as well as questions on glove-related symptoms, was mailed to the subjects. The median age for NRL allergic subjects was 40 years (range 23-62), and the diagnosis of occupational latex allergy had been made six years (range 2-16) before the present study. The WAI scores were on average lower among the sensitized subjects as compared with their nonsensitized controls. Even after removing the contribution of the presence of allergic eczema, diagnosed by a physician, from the original WAI score, the proportion of NRL allergic subjects and the control subjects in the good work ability category were 34% and 53%, respectively. Ten health care workers (31%) had changed occupation and one early retirement had occurred after sensitization to NRL. The sensitivity and specificity of the present self-administered questionnaire as an indicator for latex allergy was 84% and 98%, respectively. In conclusion, there is a clear association between NRL allergy and a decrease in the WAI among health care workers, which cannot be explained by age, gender, profession, or history of atopy.