Background: Acrylamide (ACR) naturally forms during high-temperature cooking of food. Many studies concluded that ACR has neurological, reproductive toxicities, and can produce carcinogenesis. However, the toxic effect of acrylamide on diaphragmatic muscle is not fully investigated. Objective: To evaluate the effect of acrylamide on diaphragmatic muscle and the effect of swimming exercise on diaphragmatic muscle after exposure to acrylamide. Materials and methods: Thirty white male albino rats classified into three groups, control, acrylamide, and (swimming & acrylamide) groups. Muscle enzymes were assayed. The diaphragm was weighed, and diaphragmatic muscle contractions were recorded and assessed histologically. Results: Acrylamide group significantly increased Creatine kinase-MB (CK-MB) and LDH insignificantly while Troponin I and T decreased. Acrylamide increased Malondialdehyde (MDA) and decreased Superoxide dismutase (SOD). Swimming exercise with acrylamide increased LDH, SOD, decreased Troponin I and T and MDA. Acrylamide increased diaphragmatic muscle weight and decreased muscle contraction immediately and after 30 minutes of activity, swimming exercise returned the weight of the muscle near to normal and increased contractions. Histologically, acrylamide group showed degeneration, splitting, fatty and cellular infiltration, dilatation and hemorrhage of the blood vessel, reduction of glycogen and decrease expression of desmin. Swimming exercise improved the histological architecture of the diaphragmatic muscle, increased glycogen content and the expression of desmin. Conclusion: Acrylamide induced muscle myopathy by oxidative stress, muscle dystrophy, reduction of glycogen content and decreased desmin expression with reduction of diaphragmatic muscle contraction. Swimming exercise ameliorated the effect of acrylamide on diaphragmatic muscle by reversing the previous undesired effects of acrylamide.