An easy, fast and inexpensive method to determine the mean pore size of a microfiltration ceramic membrane is offered by the wicking technique combined with electrical resistance measurements. Mean pore size is derived from the measured rates of capillary rise of different liquids of known surface tension through the ceramic membrane, via the Washburn equation. We used low-energy liquids for which the contact angle theta approximate to 0, such as hydrocarbons, and we determined the tortuosity of the membrane pores from electrical resistance measurements so that the mean pore radius was the only unknown in the Washburn equation. The mean pore diameter of the ceramic membrane was also determined from Mercury Intrusion Porosimetry (MIP) far comparison. It was found to be in very good agreement with that afforded by the wicking technique.