An insulating concrete block adapted to be interlocked with other insulating concrete blocks to form an insulating concrete form for casting concrete. The insulating concrete block including a first foam panel and a second foam panel supported in a spaced apart, parallel relationship to form a concrete receiving cavity. Each of the first panel and the second panel having a top end, a bottom end, a first end, and a second end. The top end and the bottom end of each of the first and second panels having an outside row of a plurality of projections and an inside row of a plurality of projections. The projections of the outside row being spaced apart to define a plurality of recesses and the projections of the inside row being spaced apart to define a plurality of recesses with the projections of the outside row being adjacent to the recesses of the inside row and the recesses of the outside row being adjacent projections of the inside row. At least some of the projections of the inner row are set back from an inner edge of the panel such that when one panel is interconnected with a like panel a plurality of spaced apart recesses are formed along an inner face defined by the interconnected panels.