Aim: Zeolites induce the proliferation and differentiation of cells of the osteoblast lineage. Application of zeolite in pulpotomized young permenat teeth had not been investigated. The objective of this study was to investigate histologicaly the capability of zeolite to induce dentin bridge formation and compare it with calcium hydroxide. Subjects and methods: Four dogs aged 12-24 month were included in the present study. In each dog, pulpotomy procedures were carried out in four premolars teeth in each quadrant and restored with one of the experimental materials in a way that teeth in each quadrant restored with one material differ from that of the contralateral quadrant. Specimens were harvested on the sixth week after operation and twelfth week after operative procedures, prepared and examined histologically by H&E (haematoxylin and eosin) stain, there were wide histological differences between the groups of this study along the different intervals of the study. Results: The result of the present study revealed inflammatory response of pulp tissue to both tested materials with various degrees that were subsided by time only in calcium hydroxide group. Calcium hydroxide has a powerful agent for regenerative effect on pulp tissue with dentin bridge formation. On the contrary; pulp degeneration and necrosis were the end results of pulpotomy with zeolite material. Conclusion: Calcium hydroxide could induce dentin bridge formation while zeolite failed.