Between 1967 and 1977, 395 consecutive cases of glomerulonephritis (GN) were collected by a Copenhagen study group. The diagnosis was established by histological and biochemical criteria. Light microscopy investigations of thin silver‐stained sections were applied. In a follow‐up in 1980 all cases were categorized by one of the following end points: death without uremia, uremia, recovery, or censored cases. The course is presented in figures showing the cumulated distribution of outcomes in relation to observation time. Each histological subgroup of GN had its own characteristic course with respect to initial rates of changes in the renal state, as well as to frequency of recovery, uremia and death. The prognosis was good in minimal changes GN and proliferative GN, bad in unclassified GN and worst in extracapillary GN. When part of a connective tissue disease, GN carried a poor prognosis. We conclude that histological classification of GN based on light microscopy offers a reliable means of predicting the long‐term prognosis.