The author reports the results of a double-blind, paired-comparison study using saline sclerosant plus or minus heparin additive. The study was designed to elucidate the effects of increasing concentrations of hypertonic saline with regard to vessel diameter, clinical efficacy, complications, and discomfort. Six hundred women with bilaterally symmetrical starburst telangiectasias or varicose veins were entered into the study. Sodium chloride 11.7% appeared to be the minimal sclerosant concentration of saline that produced the most effective vein sclerosis of vessels of less than 8 mm in diameter, while producing the least morbidity. The optimal concentration of the sclerosant may vary with the diameter of the vessels under therapeutic consideration.