We prove that operators satistying weighted inequalities with radial weights are bounded in mixed-norm spaces of radial-angular type, even with a weight in the radial part. This is achieved by using the usual extrapolation methods, adapted to the radial setting. All the versions of the extrapolation theorem can be adapted to this setting, and in particular we get results in variable Lebesgue spaces and also for multilinear operators. Furthermore, quantitative estimates are obtained with this approach, but their sharpness remains an open question. K E Y W O R D S extrapolation of weights, mixed-norm spaces, Muckenhoupt weights, variable exponent M S C ( 2 0 1 0 ) 42B20, 42B25, 42B35 1482