Fentanyl buccal tablets place the tablet at the buccal site (above a rear molar, between the upper cheek and gum) and wait until it dissolves, but some patients may not be able to retain it due to defects of the maxillary molars. The aim of this study was to evaluate the effectiveness and safety of fentanyl buccal tablets when they were used outside the buccal site. Seven patients were treated with fentanyl buccal tablets outside the buccal site. For each of 5 episodes in which effective dose was identified, were investigated to average pain intensity assessed on a 0 to 10 numerical rating scale at 30 min postadministration and reduction in pain intensity of more than 33%. Pain intensity significantly decreased at 30 min postadministration in 5 patients with effective doses identified (p<0.001). In 92.0% of episodes treated, there was a reduction in pain intensity of more than 33%. Adverse events were somnolence and nausea with mild. However, these effects did not result in discontinuation of medication. Our findings suggested that fentanyl buccal tablets can be used effectively and safely even when patients used outside the buccal site.