This paper presents the effects of precursor concentration on different properties of the V2O5 nanorods (NRs) grown by using spray pyrolysis technique. The V2O5 NRs with different precursor concentrations of VCl3 such as 0.05 M, 0.10 M, 0.15 M, and 0.20 M were prepared on the silicon (Si) substrates. The structural characteristics of NRs were investigated by using the XRD diffraction technique. The morphological and optical characteristics of V2O5 NRs were investigated by using a field emission scanning electron system and photoluminescence spectroscopy (PL), respectively. The V2O5 NRs based metal semiconductor–metal (MSM) photodetectors at different precursor concentrations were fabricated. The surface morphology results revealed the formation of dense V2O5 NRs that covered the entire substrate surface at 0.20 M precursor concentration. The PL emission spectra indicated a high intensity green emission around 525 nm (Eg = 2.36 eV) that was associated with the transitions of electrons between the bottom of the V-3d split-off level of the conduction band and the O-2p level of the valence band. The photo-response of the fabricated device was found to be maximum at 0.20 M concentration. The spectral responsivity of the device prepared with 0.20 M concentration was noted to be 0.042 A/W under 530 nm light at 3 V applied bias voltage. The response time and photosensitivity of the MSM device at 0.20 M were estimated to be 0.167 s and 8.6 × 103%, respectively. The results of this study demonstrated that V2O5 NRs with optimized precursor concentration act as a promising material for the MSM photodetector application. © 2019, The Minerals, Metals & Materials Society.