•Thermal conductivity, diffusivity and specific heat of a ferrofluid were measured.•All these thermal parameters can be externally controlled with a magnetic field.•The magnetic control is due to particle agglomerations induced by field.•The measured thermal conductivity is compared with some theoretical models.•Experimental results are well explained by Maxwell and Hamilton-Crosser models. The effective thermal conductivity, keff, for a kerosene-based ferrofluid with magnetite particles was determined, both in absence and presence of a static magnetic field, H over the range (0–90) kA/m. In zero polarizing field, keff of the ferrofluid is greater than the thermal conductivity of the carrier liquid (kerosene) kF, and increases greatly by applied of the static magnetic field. The obtained experimental results for keff of the ferrofluid sample, were compared with the computed values of keff using four theoretical models of the thermal conductivity. The effective specific heat (Ceff) and the effective thermal diffusivity (Deff) were also computed, both in the absence and presence of the static magnetic field. The obtained results show that all the investigated thermal parameters of the ferrofluid can be externally controlled by means of the magnetic field. These results are of particular practical importance and suggest that the investigated ferrofluid may be a potential candidate for incorporation into heat transfer devices and other thermal applications.