The value of current diagnostic methods (clinical examination, microscopy, mycological culture) was compared with a new slide latex agglutination (SLA) test for the diagnosis of vaginal candidosis in 224 women attending a genito-urinary medicine clinic. Candida albicans was isolated from 44 (19.6%) of women but just less than half of this number (21) had clinical candidosis. Clinical examination correctly identified 81% of women with candidosis but the predictive value of a positive clinical diagnosis was only 51.5%. Microscopical examination of a Gram-stained vaginal smear was also inaccurate and yeasts were seen in smears from only 42.9% of women with candidosis. Cultures were positive in 95.2% of those with candidosis, but 54.6% of women with positive cultures showed only commensal carriage. Overall, the SLA test was more successful. It was as sensitive (81%) as clinical diagnosis in identifying patients with candidosis but it was more specific (98.5%) than the other diagnostic criteria and had the highest overall test efficiency (96.8%).