AbstractSelf‐curing poweder‐liquid admixed acrylic systems are used for internal fixation of total hip and total knee prostheses. Gel permeation chromatography revealed that the polymer chain length distributions of set cements were basically unaffected by their curing pressures. However, a decrease of approximately 11% in porosity coupled with a measured increase in mechanical strengths could be induced through the use of high curing pressures well beyond those attainable by the surgeon in the current arthroplasties. The conclusion of the investigation was that, to improve such cements, attention should be focused on elimination of porosity rather than attempting to produce higher degrees of polymerizat