Background Currently, patients with dysphagia are receiving dietary management that deviates from their original swallowing function. Objective To evaluate the clinical significance of fibreoptic endoscopic evaluation of swallowing (FEES) and dietary intervention (DI) by multi‐professional collaboration during visit care for determining the actual oral intake status in patients with dysphagia. Methods Five hundred and eighteen patients with dysphagia underwent FEES, focusing on the penetration‐aspiration scale, and DI. Oral intake status was categorised using the functional oral intake scale (FOIS). FOIS scores at the first visit, after FEES, and at the reassessment were compared. Results At the first visit, 34.7% of the patients had an FOIS score of level 1 (no oral intake) and 65.3% had a score of level 2 or higher (capable of oral intake). Following FEES, 7.1% of patients had an FOIS score of level 1, and 44.4% had a score of level 2 with resumption of oral intake. At the reassessment, 489 patients (94.4%) were capable of oral ingestion (FOIS level 2 or higher). There were significant differences between the distributions of FOIS scores at the first visit and following FEES (P < .01) and between those at the first visit and at the reassessment (P < .01). Regarding tube feeding, 17 (5.9%) of 289 patients, who had received tube feeding at the first visit, were completely capable of oral intake following FEES and at the reassessment. Conclusion Appropriate evaluation of swallowing function using FEES and DI helps to understand the definite swallowing function in patients with dysphagia.