The objective of this study was to assess the efficacy and safety of liposomal heparin spray-a new formula of topical heparin delivery. This was a randomized, multicenter, controlled open clinical trial with 2 parallel groups. Forty-six outpatients with clinical signs of superficial venous thrombosis (SVT) were treated with either topical liposomal heparin spraygel (LHSG) (Lipohep Forte Spraygel, 4 puffs of 458 IU tid (n = 22) or with low-molecular-weight heparin (LMWH) (Clexane 40 mg once a day (n = 24), administered subcutaneously (sc). Main outcome measures were efficacy parameters (improvement of local symptoms-pain control and planimetric evaluation of erythema size, duplex Doppler assessment of thrombus regression) and safety parameters (documentation of adverse events, with particular reference to deep vein thrombosis [DVT] by duplex sonography, and patients' and investigators' assessment of drug tolerance). Patients' and investigators' subjective assessment of efficacy of treatment and change in basic biochemical parameters were defined as secondary outcome measures. Statistical analysis was performed with use of Wilcoxon test, Mann-Whitney U-test and Chi-square test. Regression of SVT-related symptoms, including pain, erythema, and thrombus presence, was shown as comparable in LHSG and LMWH groups. These results were corroborated by efficacy assessment by investigators and patients. Three cases of deep venous thrombosis in heparin spraygel and 1 in heparin sc group were reported. No significant adverse reactions were observed in the spraygel group, but 1 serious allergic reaction was observed in the LMWH group. Tolerance of new formula heparin was assessed as good. Heparin spraygel-a new topical mode of heparin application, seems a promising method of heparin delivery. This initial study has demonstrated comparable efficacy and safety of LHSG and LMWH in local treatment of SVT. These findings should be confirmed by further extensive study that will reach appropriate statistical power to support such conclusion, for despite heparin treatment, significant risk of DVT was demonstrated in both groups.