We present a male infant, born at term, who collapsed and died at 30 minutes of age. Autopsy demonstrated concordant atrioventricular and discordant ventriculo-arterial connections with premature closure of the oval foramen, which bulged markedly into the left atrium. Premature closure of the oval foramen is rare in the setting of transposition. As far as we know, there have been only three previously reported cases.