In this paper, a probabilistic analysis of an offshore monopile foundation embedded in a spatially varying clayey soil was performed. An efficient Kriging-based probabilistic approach using a multipoint enrichment was adopted. The aim is to compute the failure probability against exceeding a threshold value on the monopile head rotation. The proposed probabilistic approach was shown to significantly reduce the computation time with respect to the classical Kriging-based approach. Some probabilistic numerical results are presented and discussed.