Numerical and analytical investigation of favourable pressure gradient influence on the characteristics of dynamic boundary layer is presented in this work It is shown that at certain value of pressure gradient in the laminar boundary layer asymptotic conditions are reached, when skin-friction coefficient has no dependence on Reynolds number as at asymptotic suction of the boundary layer through the porous wall. There is some analogy between these two cases of the flow: both at the suction through the porous wall and in the boundary layer of the accelerated flow there is cross-flow directed from the outer boundary to the wall. (C) 2010 Elsevier Ltd. All rights reserved.