The aim of this study was to investigate the immediate effect of olfactory stimulation using black pepper oil (BPO) combined with sour bolus solution on suprahyoid muscle activation in stroke patients with dysphagia. Twelve stroke patients with dysphagia participated in this study. For all subjects, the suprahyoid muscle activation was measured using surface electromyography (sEMG) during swallowing of four types. Prior to measurement, one of the following four stimulations were applied: odorless+distilled water (ODW), odorless+sour bolus (OSB), black pepper oil+distilled water (BPODW), black pepper oil+sour bolus (BPOSB). The order of swallowing of four types was random, and the subjects swallowed three times for each sensory stimulation, with a rest period of 5 min after finishing each sensory stimulation. Repeated measure ANOVA was used to calculate the mean and maximum values of suprahyoid muscle activation with four sensory stimulations from sEMG. while OSB and BPOSB had a significant effect on mean and maximum values of suprahyoid muscle activation, ODW and BPODW did not have a significant effect (p<.05). The olfactory stimulation using BPO combined with sour bolus solution or sensory stimulation using sour bolus solution may have a positive effect the improvement of suprahyoid muscle strength in stroke patients with dysphagia.