THE FIRST English record of an intracranial aneurysm was reported by Sir Gilbert Blane2in 1800. In this historic case the autopsy was done by Hunter and Holme and was witnessed by Blane and Jenner. Bilateral aneurysms were found. Subsequent to this, reports of bilateral intracranial aneurysms found at autopsy or operation have appeared sporadically in the literature: Bourneville3(1868) reported 1 case; Bartholow1(1872), 8 cases; Pitt13(1890), 2 cases; Fearnsides and Cantab7(1916), 3 cases; Conway5(1926), 1 case; Shore18(1928), 1 case; Schmidt17(1930), 2 cases; Magner12(1935), 1 case; Bozzoli4(1937), 1 case; McDonald and Korb11(1939), 9 cases; Hamby8(1942), 1 case; Riggs* (1943, 1952), 13 cases, and Poppen14(1951), 3 cases. With improvement in techniques of visualization of intracranial arteries and more frequent surgical intervention in cases of aneurysm, it was