The main objective of the paper is to assess the quality of the SMS service. At the beginning, its operation is described in accordance with ETSI specification. Then there are presented main parameters affecting the quality of short message service such as SMS Successful Ratio Completion Rate for SMS and End-to-end delivery time for SMS. Subsequently, a measuring position is presented, consists of a server and several computers connected in a local and then there is explained its operation principle, and further measurements using MedOS scale proposed by the authors.