Objectives: The aim of this study was to see if earlier findings about factors associated with well-being could be replicated in a large population-based sample in Sweden. To the best of our knowledge, no research on well-being has been conducted on such a large population in a country, which by most standards is regarded as one of the most fortunate in the world. With its economic wealth and highly developed social welfare and health care system, Sweden is a country where the conditions for a high level of well-being would appear to be met. Methods: 10,441 randomly selected Swedish citizens, aged between 20 and 64 years, living in Stockholm County, completed a questionnaire covering issues such as demographics, social network and psychological well-being. The data were collected during the years 1998–2000. Results: Male gender, greater age, cohabiting, good childhood conditions, support from friends, sound financial situation and absence of negative life events were positively associated with well-being and explained 20% of the variance. Conclusion: The findings replicated earlier studies. Factors associated with well-being seem to remain the same, and are still explaining only a small part of the total variance, despite different measurements, time, sample sizes or country of origin. Therefore, research on well-being needs to take a new turn, by placing less focus on external factors and more focus on the internal factors, such as a person’s personality and coping strategies.