The Statute of Limitations (Amendment) Act 1991 (No. 18) introduces significant reforms to Ireland's limitation periods, specifically aimed at rectifying injustices in personal injury cases, particularly those related to medical negligence and industrial diseases. Previously, a rigid three-year limitation period commenced from the date of the wrongful act, often preventing victims from pursuing claims once they became aware of their injuries. The 1991 Act improves fairness by implementing a 'date of knowledge' test, which commences the limitation period when the plaintiff is aware or ought to be aware of essential facts regarding the injury, its significance, wrongful causation, and the identity of the wrongdoer.

This amendment also considers various factors, such as medical advice and circumstances of concealment, when assessing reasonable knowledge, thereby enhancing judicial discretion. Further provisions address claims involving minors, individuals under disability, and those related to fraud or mistake, ensuring that vulnerable parties are not unduly limited. Overall, this landmark reform aligns Ireland with modern common law practices, offering a more equitable framework for addressing claims.