A louvre blade retention system for use in a louvre windows system, the retention system including a louvre end clip mounted relative to a louvre channel, the louvre end clip having at least one longitudinal recess therein to receive an end portion of a louvre blade and at least one transverse opening, a louvre blade having at least one opening therethrough in the end portion and a retaining member adapted to be received through the aligned at least one transverse opening in the louvre end clip and the at least one opening through the louvre blade in order to fix the louvre blade to the end clip.