Abnormalities in taste function may contribute to poor dietary intake in the elderly, and in patients with renal failure or cancer. This study examined the effect of age on taste thresholds, and taste thresholds adjusted for age, in patients with renal failure with and without dialysis, and patients with cancer receiving chemotherapy and/or radiotherapy. Three groups of healthy volunteers aged 21-34 (n=26), 36-61 (n=13), and 69-94 (n=24), were recruited for the study on the effect of age. Nineteen patients with chronic renal failure on chronic ambulatory peritoneal dialysis (CAPD) and 11 age-matched chronic renal failure patients not yet requiring dialysis were recruited to examine the effect of chronic renal failure on taste function. Twenty-four inpatients with various types of cancer were recruited from a clinical oncology ward. Taste threshold was measured using commercial flavors supplied by Firmenich (pork, beef) and the ascending forced-choice method. Results showed that taste threshold increased with age. No abnormality in taste threshold was observed in patients with chronic renal failure with and without dialysis, and in patients with cancer. However, altered taste occurred in a large number of these patients. Abnormal taste function is present in healthy elderly people, and in patients with chronic renal failure and cancer. The nature of the abnormality differs among these groups, consisting of elevation of taste threshold in the elderly, and dysgeusia in those with disease.