Background and Purpose: Propiconazole is a systemic fungicide from the group of triazoles that is used to control a wide range of diseases. This poison causes the cellular, genetic and metabolic damage to the animals. The bone is a hard tissue that its contents are constantly changing. The longitudinal growth of the bone is due to the growth plate, which is a cartilaginous structure at the end of the long bones of the body. During sexual maturation, the growth of the growth plate stops the longitudinal growth of the bone. The purpose of this study was to evaluate the effect of propiconazole venom on growth plate expansion (including proliferation and hypertrophy cells) in immature rats.Materials and Methods: This experimental study was performed on 12 male Wistar rats randomly divided into two groups of control and propiconazole. Treatments were performed as oral gavage and for 28 days. On the 28th day, the animals were sacrificed and the left thigh bone was removed for histomorphometric study of the width of the thoracic appendix. The studies were performed by Rasband Wayne, 40g.1 ver, ImageJ, USA, NIH, and the results were significant by ANOVA ANOVA and test s'Tukey.Findings: Growth plaque width in the propiconazole group was significantly (P = 0.0626) less than that of the control group, which reduced the width of the reproductive area (P <0.001) and increased the width of the hypertrophied area (P=0/016).Results: Propiconazole Leads reduction of the width of the apple peptide growth plate in the immature rat rats and can be a factor in the disruption of the longitudinal growth pattern of the bone and the premature closure of the growth plate.