The aim of this study was to assess the treatment cost of tinzaparin, enoxaparin (brand and biosimilar) and bemiparin for the prevention of recurrence of venous thromboembolism (VTE) in Spain. The cost analysis model was built to estimate the initial treatment (15 days) for all patients and over a 180-day period in the secondary prevention of VTE in patients with active cancer. Specific dosage was based on each Summary of Product Characteristics. We selected data of RIETE registry to calculate the weights of different doses of enoxaparin. Drug prices were ex-factory (01/2020) + VAT (4%) + Royal Decree law 08/2010. Robustness were checked by a one-way sensitivity analysis considering patient weights. Daily cost was 10.48€ for tinzaparin, 11.24€ for biosimilar enoxaparin, 11.84€ for enoxaparin and 15.21€ for bemiparin. Tinzaparin showed a cheaper initial treatment cost with reduction between 7% (biosimilar enoxaparin) and 31% (bemiparin). In the long-term, total average cost treatment was 1.577€ for tinzaparin, 2.050€ for biosimilar enoxaparin, 2.161€ for enoxaparin and 2.408 for bemiparin. Independently of patients’ weight (40kg-100kg), tinzaparin was cheaper for all patient’s initial treatment and for the secondary prevention of VTE in patients with active cancer. The range of cost-savings with tinzaparin was 12-49% vs enoxaparin, 12-40% vs biosimilar enoxaparin and 25-48% vs bemiparin. Tinzaparin is a cost-saving alternative versus the rest of low molecular weight heparins in the treatment of VTE in Spain. This savings was observed in the initial treatment of all patients with VTE as well as in the long-term treatment of cancer associated thrombosis.