This paper presents a new method for extracting cylinders from an unorganized set of 3D points. The originality of this approach is to separate the extraction problem into two distinct steps. The first step consists in extracting a constrained plane in the Gaussian image. This yields a subset of 3D points along with a direction. In the second step, cylinders of known direction are extracted in the corresponding subset of points. Robustness is achieved by the use of a random sampling method in both steps. Experimental results showing the extraction of pipes in digitized industrial environments are presented.