Hoof preparation and shoe fit are integral to the long term soundness and athletic ability of horses. The farrier influences the balance of the hoof by both the trimming and the shoeing procedure. The goal of this study was to investigate and quantify the influence of the farrier on hoof parameters by trimming. Forty Warmblood horses ranging in age from 6-12 years and withers height 162-172 cm were included. They were divided into six groups consisting of six or seven horses each, shod by one of six different farriers. The hoof's of the horses were radiographed twice using a standardised method before and after trimming. Measurements were taken from digitalised radiographs using a software program. Significant differences were identified between farriers for almost all parameters on the lateromedial radiographic views after two consecutive trimming procedures. Comparing the results of both trimming procedures, significant differences for several farriers Were found in the lateromedial and dorsopalmar views. There were significant differences for most of the measured hoof parameters between the six farriers and between consecutive trimmings of the same farrier. The results underline the individual influence of the farrier on hoof shape and balance.