We investigated the effect of Mo addition to MgB2/Ag tapes fabricated by the ex situ PIT method. The heat treatments were carried out at 600 degrees C for 24 h under At atmosphere. The structural development, microstructures, superconducting properties and critical current density were characterized by means of XRD, SEM, M-T and M-H measurements. XRD and SEM studies indicated that Mo, not reacting with matrix of MgB2, was formed. The T-c of the tapes decreased in all the addition levels. The maximum J(c) value was obtained to be 1.2 x 10(5) A cm(-2) at 10 K for pure MgB2 tape. Decrease of J(c) was observed with increasing the Mo concentration. The J(c)-H characteristics of the tapes were decreased by the addition of Mo. This is considered to be due to the reduced flux-pinning force in the material. (C) 2007 Elsevier B.V. All rights reserved.