In this work, the epitaxial overgrowth of high and smooth GaAs mesas is presented. GaAs mesas of sidewall slope 35degrees, 40degrees, 45degrees, and 55degrees were first prepared by wet-chemical etching in H3PO4, H2O2, H2O based solution. Then the metallorganic chemical vapour deposition was used for the mesas overgrowth. The influence of the growth conditions-temperature, V/III ratio, and growth rate-on the mesa-sidewall morphology was studied using optical microscopy. scanning electron microscopy and atomic force microscopy. We show that the sidewall quality is very high for all mesa slopes for growth rate 0.6mum/h, V/III ratio 383. and growth temperature 640degreesC. Grown structures reveal strong tendency for faceting into, {110} crystallographic planes. (C) 2002 Elsevier Science B.V. All rights reserved.