Health-related quality of life (HRQoL) measured on population level may be useful to guide policies for health. This study aims to describe the HRQoL; in EQ-5D dimensions, mean rating scale (RS) scores and mean EQ-5D index values, in the general population, by certain disease and socio-economic groups, in Stockholm County 1998. The EQ-5D self-classifier and a RS were included in the 1998 cross-sectional postal Stockholm County public health survey to a representative sample (n = 4950, 20-88 years), 63% response rate. Mean RS score ranged from 0.90 (20-29 years) to 0.69 (80-88 years), mean EQ-5D index value ranged from 0.89 (20-29 years) to 0.74 (80-88 years). For different diseases mean RS scores ranged from 0.80 (asthma) to 0.69 (angina pectoris), mean EQ-5D index values ranged from 0.79 (asthma) to 0.66 (low back pain). The mean health state scores (RS and EQ-5D index) were 0.06 lower in the unskilled manual group than in the higher non-manual group after controlling for age and sex (p < 0.0001). This difference was 0.03 after controlling also for different diseases (p < 0.0001). In conclusion, our results show that the HRQoL varies greatly between socio-economic and disease groups. Furthermore, after controlling for age, sex and disease, HRQoL is lower in manual than in non-manual groups.