A clinical, bacteriological, and immunological study with reference to hemolytic streptococcal infection has been made in 10 patients. These individuals were observed during their acute glomerulonephritis, throughout a subsequent healed period, and during and following a subsequent infection with the hemolytic streptococcus. In 8 of these patients the urine remained entirely normal despite the subsequent hemolytic streptococcal infection. In 2 patients there developed transient gross hematuria without significant albuminuria. No one of the 10 patients studied has developed the chronic form of glomerulonephritis.