The fracture conductivity created in the acid fracturing process is critical to the success of this stimulation method but is difcult to predict. We have conducted a series of experiments in which core samples were acidized in a cell that allows for linear flow through a vertical fracture with fluid loss through the cores. The fracture conductivity created was then measured as a function of closure stress. We find that increased acid contact time sometimes results in lower fracture conductivity, fluid loss can increase fracture conductivity, and the Nierode-Kruk correlation accurately predicts the effccts of rock embedment strength and closure stress on acid fracture conductivity. We also observed that high fracture conductivity is created when the acid forms a deep channcl in the fracture.