the combinatorics of the genocchi numbers was developed by dumont and various co-authors in the 70's and 80's. more recently, bousquet-melou, claesson, dukes, kitaev and parviainen showed that the 2+2-free posets are in bijection with so-called ascent sequences and with non-negative integer valued upper triangular matrices which have no zero rows or columns. we will show how the genocchi numbers can be interpreted as the number of up-down ascent sequences thus connecting these various classes of combinatorial objects.