A parametrization of all orthogonal wavelet bases for Haar multiresolution analysis is derived. The bases generated by three piecewise constant wavelets {ηi(x, y)}, i = 1, 2, 3, supported on [0, 1] × [0, 1], with values aij ∈ R, i = 1, 2, 3, j = 1, 2, 3, 4 are considered.