Background: Subclinical myopathy is an earlier stage that can be easily managed to prevent or delay the associated complications and progression to evident myopathy. Objective: To evaluate subclinical manifestations and distribution of muscle affection in diabetes mellitus (DM), chronic liver disease (CLD) and chronic kidney disease (CKD). Patients and methods: The study includes 60 patients who were classified into 3 equal groups: Group 1 included diabetes mellitus cases, group 2 included chronic liver disease cases, group 3 included chronic kidney disease cases and another 20 normal individuals as control who were age- and sex-matched (Group 4). The study was conducted at Outpatient Clinic and Inpatient Neurology Department at Mansoura University Hospitals. Four groups were subjected to Electromyography, Magnetic resonance imaging and laboratory investigations. Results: There was statistically significant difference between the studied groups regarding the CK (creatine kinase) and LDH (lactate dehydrogenase) levels. The CK level was higher in CLD and CKD groups than in DM and control groups but within upper normal level. The pattern of myopathy in DM cases was more in proximal than distal muscles at upper and lower limbs. In CLD cases, the myopathic pattern at upper and lower limbs were close in proportions. The pattern of myopathy in CKD cases was more in proximal than distal muscles at upper and lower limbs. The distribution of myopathic pattern in control group was 5%. Conclusion: Subclinical myopathy isn't uncommon in DM, CLD and CKD. CK level is high in CLD and CKD patients but within normal upper limit that need further follow up for diagnosis of myopathy.