A number of different pyrolysis procedures were investigated in order to achieve higher oil yields from an immature type I oil shale than obtained under static retorting conditions. Both nitrogen and steam gases increased yields as anticipated: Steam achieving comparable yields to nitrogen but at much lower gas velocities. The composition of the tars varied considerably, steam increasing the concentration of alkenes. In coprocessing the oil shale with a Turkish lignite in the Heinze retort, oil yields were higher than predicted principally due to extraction of the lignite by pyrobitumens obtained from the oil shale. Fixed bed hydropyrolysis of the shale at 15 MPa resulted in oil yields of 75% daf shale. The use of a dispersed sulphided molybdenum catalyst increased the oil yield to over of 80%.