Hypoglycaemia from antihyperglycaemic drugs may have a significant impact on patients' health-related quality of life. Combination use of metformin and a sulphonylurea has become increasingly common; yet, the impact of hypoglycaemia on quality of life in these patients is not well documented. To examine patient-reported experience of hypoglycaemia, worry about hypoglycaemic symptoms and the impact of hypoglycaemia on patients' quality of life associated with use of sulphonylurea co-administered with metformin. This was an observational, cross-sectional, multi-centre study. A total of 98 primary care centres in France during October to December 2005. A total of 400 patients with type 2 diabetes, who were > or = 35 years old and who had been treated with metformin and a sulphonylurea for at least 6 months, completed questionnaires during their usual primary care office visit. Frequency and severity of hypoglycaemic symptoms in the past 6 months, the Worry subscale of the Hypoglycaemic Fear Survey-II (HFS-II) and the EuroQol-5 Dimensions (EQ-5D) questionnaire. A total of 136 (34%) patients reported experiencing hypoglycaemia, of whom 78 (58%) experienced mild, 40 (30%) experienced moderate and 16 (12%) experienced severe or very severe symptoms. Mean score on the HFS-II Worry scale was higher for patients who reported having hypoglycaemia than for those who did not (19.0 vs. 10.2; p < 0.0001) and increased with severity of hypoglycaemic symptoms. In linear regression analyses, more severe symptoms of hypoglycaemia were significantly associated with higher scores on the HFS-II Worry scale (p = 0.0162) among patients with hypoglycaemic symptoms. Summary scores on the EQ-5D were lower for patients who reported hypoglycaemia than for those who did not (p = 0.0001) and, in multivariate analysis, the experience of hypoglycaemia was negatively associated with the EQ-5D summary score (p < 0.0001). The occurrence and severity of hypoglycaemic symptoms were associated with increased patient worry about hypoglycaemia and lower health-related quality of life among type 2 diabetic patients being treated with both metformin and a sulphonylurea.