Lambdoid craniosynostosis is an uncommon condition, with an incidence of 1 per 33,000 live births. Its etiopathology remains controversial. Although many forms of syndromic and nonsyndromic craniosynostosis demonstrate an inherited pattern, few articles have reported lambdoid craniosynostosis in the same family. In this article, we report lambdoid synostosis in a father and son. A case review is performed. A full-term male infant was delivered by cesarean delivery because of failure to progress. He presented at 3 years of age with right unilateral lambdoid craniosynostosis with facial asymmetry and lateral deviation of his jaw, with occlusal abnormality. At presentation, the father reported skull surgery during his infancy for unilateral lambdoid craniosynostosis. Review of the computed tomographic scan of the child demonstrated a plagiocephalic appearance of the calvarium with frontal bossing and a fusion of the lambdoid suture on the right sides. The brain parenchyma showed no abnormality. The review of his father's surgical record from 33 years ago and of his computed tomographic scan ordered by our team confirmed the diagnosis of previous lambdoid craniosynostosis. Only 2 previous cases of familial isolated lambdoid craniosynostosis have been previously described in literature. Although the genetic basis has been established for many types of craniosynostosis, the etiopathogenesis of isolated lambdoid synostosis has not yet been established. We report the third case of inherited unilateral lambdoid craniosynostosis. The genetic pathogenesis of lambdoid craniosynostosis will be discussed.