Background: Flat foot deformity is considered a common chronic foot and ankle condition that is known to be associated with high incidence of lower extremity injuries in the population due to abnormal foot mechanics. Objective: To determine the prevalence of calf muscle tightness in asymptomatic flat foot subjects. Method: One hundred and seventy five flat foot subjects (male and female) their age ranging from 20-40 years participated in the study. Gastrocnemius and Soleus muscle tightness was assessed through measuring ankle dorsiflexion range of motion by using fluid-filled bubble inclinometer from two positions sitting straight knee for gastrocnemius muscle testing and prone bent knee for soleus muscle testing. Result: The prevalence of gastrocnemius tightness was 76.6% with 95% CI of 69.76- 82.23%. The prevalence of soleus tightness was 15.42% with 95% CI of 10.82- 21.51%. There was a significant increase in the prevalence of gastrocnemius and soleus tightness in female subjects compared with males (p < 0.01).Conclusion: Flat foot deformity is associated with gastrocnemius muscle tightness and a significant increase in the prevalence of gastrocnemius and soleus tightness was found in female subjects compared with males.