The objective was to study the association between chronic diseases, symptoms, and poor self-rated health among men and women and in different age groups, and to assess the contribution of chronic diseases and symptoms to the burden of poor self-rated health in the general population. Self-rated health and self-reported diseases and symptoms were investigated in a population sample of 6,061 men and women aged 35-79 years in Värmland County in Sweden. Odds ratios (OR) and population attributable risks (PAR) were calculated to quantify the contribution of chronic diseases and symptoms to poor self-rated health. Depression, neurological disease, rheumatoid arthritis, and tiredness/weakness had the largest contributions to poor self-rated health in individuals. Among the elderly (65-79 years), neurological disease and cancer had the largest contribution to self-rated health in men, and renal disease, rheumatoid arthritis, and cancer in women. Among the middle-aged (35-64 years), depression and tiredness/weakness were also important, especially in women. From a population perspective, tiredness/weakness explained the largest part of poor self-rated health due to its high prevalence in the population. Depression and musculoskeletal pains were also more important than other chronic diseases and symptoms at the population level. Even though many chronic diseases (such as neurological disease, rheumatoid arthritis, and cancer) are strongly associated with poor self-rated health in the individual, common symptoms (such as tiredness/weakness and musculoskeletal pains) as well as depression contribute more to the total burden of poor self-rated health in the population. More preventive measures should therefore be directed against these conditions, especially when they are not consequences of other diseases.