Compositions for oxidation dyeing keratin fibers, such as human keratin fibers like hair, comprising, in a dyeing medium, (1) at least one oxidation dye, (2) at least one fatty alcohol comprising more than twenty carbon atoms, (3) optionally at least one fatty alcohol having at most twenty carbon atoms, (4) at least one oxyalkylenated nonionic surfactant with an HLB greater than 5, and (5) optionally at least one oxyalkylenated surfactant with an HLB at most equal to 5, in a proportion such that the weight ratio [(4)]/[(2)+(3)+(5)] is less than or equal to 1:1. Processes comprising such oxidation dyeing compositions.
