Abstract: A magnetic writing and optical reading head for a magnetic data carrier including at least one optical focusing device (SOI.sub.1, SOI.sub.1) for focusing a beam of light onto the carrier, and a magnetic writing transducer (TMI.sub.1, TMI.sub.2) disposed on the same rail (PI.sub.1, PI.sub.2) of the head as the optical device. According to the invention, the head is characterized in that the optical device and the transducer are disposed in the immediate vicinity of one another at a distance d less than the ratio of the difference between the width of the track L.sub.p and the diameter D of the beam of light produced by the device (SOI.sub.1, SOI.sub.2) to twice the sine of the maximum azimuth angle .psi..sub.M. The invention is applicable to magnetooptical disk memories.