BACKGROUND Certain types of varicose veins can be successfully sclerosed with polyiodinated iodine (PII). Although this sclerosant is widely used in Canada and in Europe, it is not marketed in the United States. OBJECTIVE The following study was undertaken to determine whether an American polyiodinated iodine (APII) formula, compounded in a hospital pharmacy, is as effective as a commercially available brand of PII in the rabbit ear vein model. The two sclerosants were identical in composition. METHODS After being mixed with either normal saline (NS), Sclerodex, or an American dextrose-hypertonic solution (ADHS) compounded in a hospital pharmacy, each sclerosant was injected in concentrations of 0.1% and 0.5%. The veins were examined clinically and histologically 1 hour, and 2, 8, and 28 days after injection. They were examined with electron microscopy at 8 and 28 days. RESULTS When diluted with NS, Sclerodex, or ADHS and injected in a 0.1% concentration, each sclerosant produced a hyperplastic regenerating endothelium without evidence of mixed cellular infiltrates at 2 days. By 28 days, the endothelium was regenerated. When diluted with NS, Sclerodex, or ADHS and injected in a 0.5% concentration, each sclerosant produced more thrombosis, yielding a mild perivascular mixed cellular infiltrate and fibrin coagulum at 8 days and thrombus cord formation at 28 days. CONCLUSIONS When mixed with NS, Sclerodex, or ADHS, APII has the same efficacy as PII.