Administration time of 1 min for semantic verbal fluency measures can be overly long and therefore bothersome for aphasic patients because they can often retrieve only a few items after a certain period of time. The purpose of this study was to determine whether an administration time of 30 s would be more efficient in differentiating among aphasics, nonaphasic stroke patients, and normal controls. The subjects were 53 stroke patients and 28 normal controls. They had to generate as many animal names as they could within a given time. The number of animal names is gradually diminished in three groups (p < 0.001) in each time frame, that is, during the entire 60 s, the initial 30 s, and the following 30 s. The reaction time (RT) measure indicated that the RT of the aphasic patients was significantly increased compared to those of the other two groups (p < 0.001). The most optimal cutoff scores that differentiated each group are presented. These results suggest that an administration time of 30 s has discriminative validity to differentiate between the two patient groups. This shorter administration time could make the test more efficient by reducing the burden on both examiners and aphasic patients.