This paper deals with the residual deformations introduced in a thin walled pipe by laser welding. Both numerical simulations and experimental measurements have been performed. Laser welding has been adopted for an increasing number of applications. Some preferable characteristics of laser welding are high welding speed and low heat input. Laser welding of thin walled structures gives smaller residual distortions than other welding processes. One of the main objectives in this paper is to verify the theoretical finite element model by experiments. The calculated temperatures show good agreement with measured values. The calculated deformations agree fairly well with measured values except for values at the center line of the weld. Example material was steel 304.