A planning method and device for knee implants, wherein spatial data on the configuration of a patient's genicular anatomy, in particular of at least a part of the femur and/or the patella and/or the tibia, are captured in order to be inputted into a computer-assisted planning station; the movement of the parts of the genicular anatomy is recorded using a tracking and/or motion capturing method; the captured anatomical and movement data are made available to the computer-assisted planning station; a part of the patient's genicular anatomy is virtually replaced in the planning station by a sample implant and movements of the knee together with the sample implant are simulated; contact and impingement between the non-replaced parts of the genicular anatomy and the implant during the virtual movement is ascertained according to its magnitude; and wherein an adjustment of the positioning, shape or orientation of the implant or of a number of these parameters is determined until the contact and impingement become non-critical and the adjustment thus determined is defined as a suitable adjustment.