Objectives: This study set out to determine the appropriate timing for nutritional education by analyzing changes of the nutritional indicators in hemodialysis (HD) patients during 24 weeks after education. Methods: A total of 18 HD patients was included. Dietary intake was analyzed through 3-day food records and collected at baseline, 0, 12 and 24 weeks after education. Nutritional status by Patient-Generated Subjective Global Assessment (PG-SGA) and biochemical data was collected at 0, 12, 24 weeks. In order to evaluate the education effect in detail, subjects were divided into two groups; those with no education experienced and those with education experienced before this study (No-EE and EE group). Results: The intake of energy, protein, animal protein, calcium and phosphorus had increased from baseline to 24 weeks. Compared to baseline, the improvement of dietary intake was more significant at 0 and 12 week(s) than 24 weeks. The PG-SGA score showed a better nutritional status at 12 weeks (4.61 vs. 2.67 score, 0 week vs 12 week, P<0.05). The dietary intake in No-EE group was increased at 12 weeks. On the other hand, the dietary intake and nutritional status in EE group were improved at 24 weeks. There were no biochemical changes for 24 weeks. Conclusions: There was an inverted U-shaped effect in dietary intake and nutritional status for 24 weeks after education. Nutritional indicators showed the greatest improvement at 12 weeks. The PG-SGA nutritional triage recommends nutritional intervention even under the improvement of PG-SGA score. No-EE group had the greatest improvement in dietary intake immediately after education, and EE group have improved even through 24 weeks. Therefore, patients with HD for the first time should be educated at the beginning of HD and re-educated at least every 12 weeks, and patient who have had educated more than twice, should be recommended to re-educate within 24 weeks.