Although some authors previously stated that microlymphatic surgery does not have application to primary lymphedema, opposite views are reported based on the observations that the lymphatics were not hypoplastic in majority of these patients and microlymphatic surgery yielded significant improvement. The aim of this study was to compare the intraoperative findings and outcomes of primary and secondary lower-extremity lymphedema cases treated with lymphaticovenous shunts. Between December 2006 and April 2009, microlymphatic surgery was performed in 80 lower extremities with primary and 21 with secondary lymphedema. These two groups of extremities are compared according to the morphology of the lymphatic vessels and possibility of precise anastomoses, their response to the treatment, and final outcomes based on volumetric measurements during the follow-up period. The morphology of the lymphatics in secondary lymphedema was more consistent, and at least one collector larger than 0.3 mm was available for anastomosis in 20 of 21 extremities. In the primary lymphedema group, the lymphatics were smaller than 0.3 mm in 13 of 80 extremities. It was, therefore, possible to perform supermicrosurgical lymphaticovenous anastomosis in 84% of extremities with primary lymphedema and 95% of extremities with secondary lymphedema. Reduction of the edema occurred earlier in the secondary lymphedema group, but the mean reduction in the edema volume was comparable between the two groups. Microlymphatic surgery, although more effective and offered as the treatment of choice for secondary lymphedema, would also be a valuable and relevant treatment of primary lymphedema.