We report the early failure of two tissue valves within hours of surgery due to the accumulation of cellular debris in two different institutions in the United Kingdom. The valves were both found at explant to be covered in a cellular material - possibly fibrin. From clinical experience and careful review of the literature we have found no other reports of such early valve failure due to the build up of material on the structure of the valve. This rare occurrence needs to be reported in the literature to forewarn clinicians of an early complication that may not be recognized yet.