The magneto-dielectric effect (MDE) in a concentrated suspension of magnetite in mineral oil has been studied as function of the applied magnetic field and of the angle Θ between directions of the electric field E and magnetic field intensity H: Θ = ∠ E, H. The maximum value of MDE was about 16% in comparison with the zero-magnetic field dielectric constant. The non-monotonic behaviour of ε(H,Θ) for some values of Θ were observed and the anisotropy parameter g = −Δε∥/Δε.1 has been found to be g = 3.14 in contrary with the predicted theoretical value g = 2.