The clinical syndrome of recurrent macroscopic hematuria, unassociated with hypertension, edema or anatomical urinary tract abnormalities, is relatively common in children and young adults. Baehr [1] in 1926 described 14 young adults with a benign and curable form of hemorrhagic who appeared to be examples of this syndrome. The syndrome is characterized by recurrent episodes of hematuria which often begin at the height of an upper respiratory infection; one of the most striking clinical features of these patients. Typically, dark urine, red blood cell casts and hematuria appear the day of, or within two to three days of, the onset of the infection. Macroscopic hematuria rarely lasts longer than two to five days and is often accompanied by transient low grade ( Because of the association of the presenting sign, hematuria, with upper respiratory infection, numerous reports have focused upon the bacterial flora of the upper respiratory tract in these patients during the attacks. Although throat cultures and/or serologic evidence for recent infection with beta-hemolytic streptococci have been found in 30 to 40% of hospitalized children in some studies [3], this incidence of presumed streptococcal infection closely approximates the average experience in hospitalized children, and no clear evidence of a regular relationship between streptococcal or other infectious agent(s) has been documented. It seems likely that the syndrome is the result of a variety of etiologic factors operating through a common pathogenetic mechanism [4]. An additional important characteristic of patients with recurrent hematuria is the rather consistently normal value of serum complement [4–6]. Since complement concentrations are low in the majority of patients with acute poststreptococcal glomerulonephritis, normal sequential complement concentrations are of great value in reducing the likelihood of that diagnosis, especially in the patient with a positive throat culture for beta-hemolytic streptococci and the recurrent hematuria syndrome. Several reports describe an incidence of recurrent macroscopic hematuria in other family members and relatives of patients with this syndrome [3, 7, 8]. Although familial nephritis, such as Alport's syndrome, is usually recognizable by virtue of a history of overt nephritic manifestations and/or deafness in relatives, this important differential diagnostic problem must always be considered in patients with symptomless hematuria.