The microstructures of Ti-Al layers produced by laser surface alloying of a Ti substrate have been investigatedfor Al contents in the range 17-36 at.-%. The alloyed layers were obtained using a continuous wave CO2 laser and a powder feed technique employing thefollowing laser processing parameters: 1·8 kW power, 3 mm beam diameter, 7 mm s -1 traverse speed, and feedrates of Al powder ranging from 0·03 to 0·07 g s -1. The microstructures were disordered lath martensite ( I. in 17 at.-%Al alloy, ordered massive and acicular martensite in 23 at.-%Al alloy, and ordered massive, acicular, and lath martensite in 30 and 36 at.-%Al alloys. The change in martensite type and morphology is discussed in relation to the available datafor the f3 to ( I. transformation in Ti alloys.