This article examines the effect of current collector (CC) roughness on the passive direct methanol fuel cell (DMFC) performance. The stainless steel has been used for anode and cathode CC. The passive DMFC has been evaluated for different roughness value of the CC. The evaluation of passive DMFC has been done on the basis of polarization test with open circuit voltage (OCV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The small mathematical model has been developed for mass transport resistance prediction for one dimensional steady state flow. It is observed that the CC roughness has significantly affected the DMFC performance. The performance of conventional passive direct DMFC with a possible minimum roughness value of CC has been compared with the new passive DMFC with an optimum roughness value of CC. The passive DMFC shows the very good performance at 4M methanol concentration with optimum CC roughness of 0.869 mu m. 2019 Elsevier Ltd. All rights reserved.