Structural and magnetic studies have been carried out on In3+ substituted NiFe2O4 having chemical formula NiFe2-xInxO4 (x = 0.0-0.30 in step of 0.05) prepared through solid-state reaction. The phase purity of the samples was investigated by X-ray diffraction technique. An analysis of X-ray diffraction patterns reveals the formation of single phase cubic spinel structure. The true lattice parameter of all the samples was calculated by extrapolating the data. The lattice parameter obtained using XRD data shows increasing trend. The XRD data was also used to study various structural parameters. The investigations of magnetic properties were carried out with the help of pulse field magnetization setup and a.c. susceptibility technique. The saturation magnetization 'Ms' and magneton number 'n(B)' both increased with the substitution of In3+ ions. An attempt has been made to correlate the experimentally observed values with theoretical models. (c) 2009 Elsevier B.V. All rights reserved.