In order to clarify the changes of the venous circulation in normal and affected hip with Legg-Ca1ve-Perthes’ disease(L.C.P.D.) and to assess the effect of intertrochanteric varus osteotomy on the venous circulation around the proximal femur in L.C.P.D., intra-osseous venography(I.O.V.) was performed before osteotomy and also 8 weeks later when K-wires or staples used at the time of osteotomy were removed. Results obtained were as follows: 1. The material was consisted of 13 normal and 17 hips with L.C.P.D.. There were 14 boys and one girl, with a mean age of 6.1 years ranged from 5 to 9 years; in two patients the disease was bilateral. 2. When the hips with L.C.P.D. were divided into four groups by the method described by Catterall, three hips were included in group II, ten in III and four in IV. 3. In I.O.V. of the proximal femoral metaphysis on 13 normal hips, the opaque medium disappeard rapidly through the local venous system around the proximal femur, and no regurgitation into diaphysis were noted. But gluteal and medial circumflex vein in each one case was not visualized. 4. Of 17 hips with L.C.P.D., an I.O.V. was carried out before and after the intertrochanteric osteotomy. The ligamentum teres and gluteal vein appeared in only 4(24%) and 7 hips (41%) before and after osteotomy. And the lateral and medial circumflex vein visualized in 12(71%) and 15 hips before osteotomy and in 17 hips, both after osteotomy. The diaphyesal regurgitation in 35 % and trochanteric venous pooling of the opaque medium in 47%, indicating venous congestion on the trochanteric region of femur, disappeared after the osteotomy. But no significant differences in their age and group of L.C.P.D. were found. All of these findings suggest that the impaired venous system around the proximal femur and increased intra-osseous pressure on proximal femur may act as one of the important role in pathophysiology of the L.C.P.D., and the intertrochanteric osteotomy might have some positive effect for the normalization of venous circulation and intra-osseous pressure in L.C.P.D..