The five-, seven- and ten-layered martensitic structures previously reported in Ni-Mn-Ga alloys have been investigated by high resolution electron microscopy (HREM). The observations confirm their nature as stacking of nearly close-packed planes with sequences (3 (2) over bar), (5 (2) over bar) and (5 (5) over bar), in Zhdanov notation, respectively. A periodicity of 12 planes with (7 (5) over bar) stacking sequence has also been observed. (C) 2003 Elsevier Science B.V. All rights reserved.