This study examined the effect of incorporating a visuo-haptic and haptic (tactual-kinaesthetic) exploration of letters in a training designed to develop phonemic awareness, knowledge of letters and letter/sound correspondences, on 5-year-old children's understanding and use of the alphabetic principle. Three interventions, which differed in the work on letters identity, were assessed. The letters were explored visually and haptically in ''HVAM'' training (haptic-visual-auditory-metaphonological), only visually in ''VAM'' training (visual-auditory-metaphonological) and visually but in a sequential way in ''VAM-sequential'' training. The three interventions made use of the same phonological exercises. The results revealed that the improvement in the pseudo-word decoding task was higher after HVAM training than after both VAM training and VAM-sequential training (which did not differ). The sequential exploration of the letters (independently of perceptual modalities involved) was not to be sufficient alone for explaining these results. Moreover, similar improvements in the letter recognition test and in the phonological awareness tests were observed after the three interventions. Taken together, the results show that incorporating the visuo-haptic and haptic exploration of letters makes the connections between the orthographic representation of letters and the phonological representation of the corresponding sounds easier, thus improving the decoding skills of young children.