Background Although the gait and balance disturbances of Duchenne muscular dystrophy (DMD) patients were evaluated by using different methods in literature, the impact of the foot and body posture on gait and balance has not been clearly described yet in DMD. Aim The aim of this study was to examine the relationship between foot-body posture and gait and balance in patients with DMD. Methods Ambulatory patients with DMD who had > 90° range of motion at ankle joint were included in the study. Foot and body posture were evaluated with the Foot Posture Index (FPI-6) and the New York Posture Rating (NYPR). The limitation degree at the ankle joint (ALD) was recorded. Gait characteristics and balance were evaluated objectively by using the GAITRite system and the Bertec Balance Check Screener ™ force platform system, respectively. Results A total of 38 ambulatory patients with DMD (age: 92.44 ± 17.91 months) were recruited. Both the right and left foot FPI-6 scores were correlated with GAITRite parameters such as ambulation time, gait speed, number of steps, and left and right stride lengths ( p  < 0.05). A relationship was determined between right foot FPI-6 score and anterior–posterior limits of stability (LoS) obtained by force platform ( p  < 0.05). NYPR score was also correlated with the postural control parameters such as left and right base of support and anterior posterior LoS ( p  < 0.05). Conclusion The current findings indicate a contribution of foot and body posture to gait and balance disorders of children with DMD. Clinical Trial Number NCT04353167, Date of registration: April 16, 2020.