The aim of this study was to analyse how plasma glucose level and diabetes mellitus (DM) are associated with chronic pain in the adult population. A structured interview and health examination study with 480 participants aged 30-65 years was carried out in Lapinlahti municipality in Eastern Finland. Chronic pain (duration of at least 3 months) was graded according to frequency: being present less often than daily, or every day or continuously (daily chronic pain, DCP). Elevated plasma glucose was defined as a plasma glucose level 6.1 mmol/l. DM diagnosis was based on self-reported diagnoses, reimbursed medication or a health examination with laboratory tests. Glucose regulation status was defined according to fasting plasma glucose level and a two-hour glucose tolerance test. Of the total sample, 90 subjects (19%) had a plasma glucose level > or = 6.1 mmol/l and 55 subjects (11%) had diabetes. The prevalence of daily chronic pain was 21% (N = 101) in all the subjects. In the subjects with a normal plasma glucose level, the prevalence was 18%, while in those with an elevated plasma glucose level it was 38%. The corresponding percentages for non-diabetics and diabetics were 19% and 42%. In the multinomial multivariate logistic regression analysis, glucose level or diabetes was associated with DCP. The odds for DCP in the subjects with an elevated plasma glucose level was 2.37 (95% CI, 1.26-4.49), and in those with DM it was 2.53 (95% CI, 1.12-5.72). Elevated plasma glucose level and DM are associated with DCP in adults.