The present study investigated 190 first-year Japanese undergraduates’ performance on the IELTS test and the factors that influenced this performance. Participants took two IELTS tests and completed a survey about their language learning history during pre-tertiary and tertiary education and about their preparation for the IELTS test. Nineteen students also participated in follow-up interviews.

Test results showed that the participants excelled at reading, followed by listening, while they were relatively much weaker in writing and speaking. Mean overall and speaking scores significantly increased, with greater gain occurring at lower proficiency levels.

Regression tree analyses were performed on the score data with 70 variables selected from the survey data as covariates. Key explanatory factors for the first and second test scores and for the subset of participants whose score increased included experience of living and/or studying abroad, motivation to study writing, amount of writing practice, and the type of test preparation (i.e. spoken fluency, test techniques).

Survey and interview data revealed that pre-tertiary education in Japan is highly focused on university entrance exam preparation, leading to a bias towards studying reading and, to a lesser extent, listening and writing, while speaking in English is virtually non-existent in the curriculum. These findings demonstrate a strong washback effect from current university entrance exams and help to explain the imbalance of skills identified using the IELTS test.

Regarding test-takers’ preparation for IELTS, they reported practicing speaking and writing, being motivated to study these skills and, as a result, perceived the greatest improvement in these skills. It is likely that this increase in practice of productive skills led to the actual increase in speaking test performance observed over the period.

Recommendations for using IELTS in the Japanese tertiary context are presented in light of the observed benefits, particularly regarding the potential for positive washback on productive skills.