Growth directions and crystallographic orientations of solidification microstructures have been measured in Al-Zn alloy near the eutectic composition. Al dendrites in Al-92 wt.% Zn alloy were found to grow along the I 10) directions while Zn dendrites in Al-96 and 98 wt.% Zn have < 10 (1) over bar0 > trunks. In the lamellar eutectic, a crystallographic relationship has been found between the dense plane of each phase, i.e. {111}(fcc) parallel to {0001}(hcp), and the dense directions, i.e. < 110 >(fcc) parallel to < 1210 >(hcp). (C) 2008 Acta Materialia Inc. Published by Mevier Ltd. All rights reserved.