This study developed a 5-step vocabulary learning (FSVL) strategy and a mobile learning tool in a situational English vocabulary learning environment and assessed their effects on the learning motivation and performance of English as a foreign language (EFL) students in a situational English vocabulary learning environment. Overall, 80 EFL students and 1 teacher participated in this study. Two learning methods were implemented. The first involved employing the FSVL strategy and the mobile learning tool in a situational English vocabulary learning environment, and the other method involved employing the FSVL strategy and traditional learning tools in a situational English vocabulary learning environment. Data were collected by conducting interviews and tests and administering the Attention, Relevance, Confidence, and Satisfaction motivation questionnaire. The results showed that the learning motivation and performance of students taught using the FSVL strategy and mobile learning tool were superior to those of students taught using the FSVL strategy and traditional learning tools in a situational English vocabulary learning environment.