The microstructures formed by magnetic colloids in the absence or presence of external magnetic fields plays a key role in the design of multifunctional nanomaterials. In this work we have carried out Brownian dynamics simulations of a dilute suspension composed by self-propelled superparamagnetic colloids, in order to study the interplay between the self-propulsion and the magnetic interaction forces in their aggregation process, when the suspension is subjected to a strong external magnetic field. This simulation method solves, numerically, the force and torque balance equations which arise after applying the Newton’s second law to the translational and rotational motion of spherical magnetic particles immersed in a Newtonian fluid. The model neglects the particle inertia, the gravity effects and the hydrodynamic interparticle interactions, which is a common practice when the system ...