This article presents the influence of service outsourcing on the structure of employment in companies. The first part portrays both the positive and negative aspects of outsourcing. It pays particular attention to such aspects as changes in the area of employment, employee resistance to externalization, the behavior of the participants towards the outsourcing partner, and some of the pathologies connected with the application of outsourcing. The second part presents the results of research carried out in a group of 110 small– and medium-size enterprises that use outsourcing in the field of accountancy and tax advice. It analyzes the influence of outsourcing on the level and the structure of employment in customer companies. The presented results indicate positive trends. A decrease in employment has been noticed in only few companies. In fact, collaboration with an accountancy office has more often resulted in an employment increase in the companies.