Several different tertiary amines have been employed to prepare the corresponding quaternised triasines from a selected monochloro-s-triazine reactive dye. The preparation conditions have been established together with suitable analytical methods. The reactivity of quaternised dyestuffs with cellulose has been determined, paying particular attention to the neutral fixation at high temperatures (100 ° C). A good neutral fixation was achieved with all the tertiary amine derivatives studied. In the case of the nicotinamide derivative, an abnormal hydrolysis reaction involving the opening of the ring was observed; this reaction led to the formation of aminotriazine instead of the expected hydroxytriazine.