Horses that had been trimmed and shod by apprentice farriers were sourced from the Royal School of Military Engineering, Melton Mowbray (37 horses) and from the Household Cavalry, Knightsbridge (54 horses). The lateral and medial hoof wall angles of both forelimbs were measured using a Ruidoso hoof gauge by the same operator. The difference between the lateral and medial hoof wall angles for each horse was calculated and the results were compared between right-handed and left-handed farriers using the Mann-Whitney U test (P<0.05). There was a significant difference in the mediolateral hoof balance obtained between right-handed and left-handed farriers for each forelimb (P<0.001). Right-handed farriers were shown to create an imbalance in 47 per cent of left forelimbs and 46 per cent of right forelimbs assessed, while left-handed farriers created an imbalance in 41 per cent of left forelimbs and 71 per cent of right forelimbs. The tendency was for right-handed farriers to over-trim the medial (inner) aspect of the left forelimb and the lateral (outer) aspect of the right forelimb; the reverse was demonstrated for left-handed farriers. Performing a risk ratio confirmed these findings.