The efficacy and safety of streptokinase and heparin in deep vein thrombosis (DVT) were compared in a meta-analysis. Randomized trials in which streptokinase (followed by heparin) and heparin alone were compared in treating phlebographically documented acute DVT were identified from MEDLINE and other sources for a meta-analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) based on the logit method were computed for each study. A fixed-effect model was used to combine the study results, enabling differences between streptokinase recipients and recipients of heparin alone to be expressed as summary ORs with 95% CIs. Significantly more streptokinase recipients achieved thrombolysis than recipients of heparin alone (summary OR, 6.24; 95% CI, 3.62 to 10.78). One study was identified as an outlier and excluded from the analysis. The meta-analysis then showed that streptokinase recipients were significantly less likely to have postthrombotic changes (summary OR, 0.40; 95% CI, 0.18 to 0.88) and postphlebitic changes (summary OR, 0.32; 95% CI, 0.12 to 0.86) in phlebographic evaluation. The frequency of major bleeding was significantly higher among streptokinase recipients than recipients of heparin alone (summary OR, 3.78; 95% CI, 1.26 to 11.32). A meta-analysis showed that, compared with heparin alone, streptokinase therapy for DVT was associated with significantly more frequent thrombolysis and major bleeding; after exclusion of one outlying study, analysis showed that streptokinase therapy was associated less frequently than heparin alone with postthrombotic changes (assessed by phlebographic evaluation) and postphlebitic syndrome.