This thesis as the majority of the task shows construction of 3D model for a two part centrifugal pump impeller using the software package CATIA V5. The introduction describes some of the basic characteristics of centrifugal pumps and impellers, as well as examples of some types. General part describes the software package CATIA V5 and some of its modules, and also software package ESPRIT. 3D model designed in CATIA and will be used as the base for machining front and rear impeller disc on a CNC machine. Construction is carried out according to the documentation of the impeller in 2D format. Intermediate step between creating 3D models and manufacturing impeller on CNC machine is the creation of the technological process. This step is performed by using the software package ESPRIT, in which we import a 3D model from CATIA, program tool path, simulate machining and generate G-code for machining on CNC. As the majority of the task is creating a 3D model for the impeller using CATIA, this step of making technological process is not covered by this thesis. After machining both impeller discs on a CNC, this thesis also shows the procedure of welding impeller discs, and final machining on conventional machines.