In horses, the use of a positive reinforcement as a food reward has been shown to enhance learning performances and to promote a positive relation to the trainer. Here, we investigated whether grooming at the whither, known to induce a decrease in the groomee’s heart rate, could be used as a primary reinforcement, by comparing it to a food reward. Twenty Konik horses (9 females, 11 males), aged 1-2 years, with no previous learning experience and no contact with humans, except for feeding, were trained to remain immobile in response to a vocal command. Training was performed 5 minutes per day for 6 days. Horses were allocated to one of two training groups: in the food-reward group (FR: n=10), the trainer hand-gave a piece of carrot to the horse after it responded correctly, while in the grooming-group (GR: n=10), the trainer scratched the horse’s wither. Duration of immobility and trainer-directed behaviours were continuously recorded. The results indicate that: (1) using food rewards facilitated learning (duration of immobility: P<0.05), whereas grooming rewards led to lower performances; (2) the type of reward has a clear effect on the horse’s attentional state during training. While no difference between both groups were scored in the first days of training, on the last day the FR group spent more time monitoring (i.e. head rotations towards the trainer), more time gazing at and expressed more investigative behaviours towards the trainer (e.g. sniffing) than the GR group (MW, P<0.05 in all cases). In conclusion, these results suggest that the use of a food reward is associated with an increase of motivation, leading to a better efficiency in promoting learning that may well have been mediated by attentional factors, while alternative such as scratching (usually use in training techniques) appears less efficient.