Introduction. Many adolescents are treated with cold or heat modalities before therapeutic exercise, but the difference between the effect of cold vs. heat on dynamic balance is not clear till now. The study aimed to determine the immediate effects of cold and heat modalities for ankle joint on dynamic balance and also to compare the impact of these modalities on dynamic balance. Methods. The study involved 30 normal adolescents of both genders aged 13-18 years. The Biodex system was used for dynamic balance assessment in each participant under 3 conditions: (1) control condition: at room temperature; (2) immediately after a 15-minute cold immersion (5°C ± 1°C) for ankle joint; (3) immediately after a 15-minute heat immersion (40°C ± 5°C) for ankle joint. For randomization, the order of cold and heat modalities was chosen randomly by using a coin flip. Results. Mixed design MANoVA revealed statistically significant changes in dynamic balance, including overall stability (oAS), anteroposterior stability (AP), and mediolateral stability (ML) after cold modality and after heat modality (p 0.05). The pairwise comparison test to compare cold vs. heat modalities determined that oAS, AP, and ML were statistically significantly improved after heat modality in comparison with cold modality (p 0.05). Conclusions. dynamic balance could be altered immediately after cold or heat modalities. it improved after heat while decreased after cold modality in healthy adolescents.