Background Malnutrition, an important problem in geriatric medicine, is becoming more recognized in hemodialysis patients, as a factor that can even worsen the prognosis and the quality of life of these patients. It is imperative for the nephrology community to recognize this syndrome of malnutrition and work to manage it. Malnutrition can be detected commonly in all age groups of dialysis patients, and it represents a sensitive marker for morbidity and mortality better than chronological age. It could also act as a major cofactor for depression and cognitive impairment development in dialysis patients. We aimed to assess the nutritive status of the elderly patients with end-stage renal disease (ESRD) undergoing hemodialysis using modified subjective global assessment score (M-SGAS) and to correlate between it and different biochemical parameters. Patients and methods A total of 100 ESRD elderly patients on regular hemodialysis were included. All patients were subjected to the following: history taking, including weight change, dietary intake, gastrointestinal symptoms, and functional capacity (nutritionally related functional impairments, comorbidity); physical examination, including decreased fat stores or loss of subcutaneous fat (eyes, triceps, biceps, and chest), signs of muscle wasting (temple, clavicle, ribs, knee, interosseous, quadriceps, and scapula), mid-upper arm and calf circumference, and BMI; malnutrition score (sum of all number) using SGAS; and laboratory investigations, including complete blood count, serum creatinine, blood urea, C-reactive protein, serum albumin, parathyroid hormone, serum calcium, serum phosphorus. urea reduction ratio, and KT/V. Results There was a decrease in anthropometric measures in both males and females, indicating that both sexes are prone to malnutrition to the same degree. On comparing between male and female patients with respect to total M-SGAS, they lie in the moderate degree of total M-SGAS, with no significant difference between males and females. There was a statistically significant negative correlation between M-SGAS and triceps skin fold, mid-arm muscle circumference, and mid-arm circumference, and also there was a statistically significant negative correlation between duration of dialysis and mid-arm circumference. Conclusion The M-SGAS can be used as reliable, rapid, and precise method for nutritional assessment in elderly patients with ESRD on regular hemodialysis. There is a high prevalence of malnutrition among all age groups, even those younger than 40 years old. Malnutrition is associated with female sex, hypoalbuminemia, increased inflammatory markers such as elevated C-reactive protein and elevated total leukocytic count, and in those with low hemoglobin level. Malnutrition also is more detected in patients with hyperparathyroidism.