The clean hands doctrine is an equitable principle that a party seeking a discretionary remedy must have acted honestly and fairly in relation to the matter in dispute. In practice, courts may refuse relief such as injunctions, specific performance, rectification, rescission or other equitable remedies where the claimant’s own conduct is tainted by illegality, bad faith, unconscionability or serious misconduct connected to the claim.The doctrine is not usually set out in legislation but is developed through case law and applied flexibly. In England and Wales and Northern Ireland, it forms part of the general maxims of equity guiding the court’s discretion. In Ireland, it similarly informs decisions on equitable relief, including in commercial, land and public law disputes. In Scotland, broadly comparable concepts arise within the equitable and public law jurisdiction (for example, the need for good faith and fair conduct when seeking reduction or interdict).Practically, lawyers should assess a client’s pre‑action behaviour, contractual performance, disclosure and general bona fides, as adverse conduct may bar or limit equitable or discretionary remedies even where a legal right is established.