Technology based firms (TBFs) require innovative products to survive and compete in the market. The creation of products that sustain the competitiveness of companies depends directly on their product development process (PDP). The objective of this research was to investigate how PDP is carried out in TBFs in innovation environments. The research is qualitative, based on multiple case studies. Three companies in technology parks in the South and Southeast of Brazil were studied. The companies produced the following products: multiparametric monitor, an ondaleta and a microfiltration system. The key findings of the research were a lack of formal PDP planning and unstructured development processes. As a contribution, the study proposes that TBFs use a milestone strategy in the PDP microphases, guaranteeing greater efficiency in product development without the need to create rigid processes in project development. The study also highlights the importance of cooperation with clients and suppliers during the revision phases of PDP. The products resulting from PDP of the companies studied were identified as incremental innovation, novel for the national market, but with established technology on the international market. Future studies should assess the evolution and learning curve in the product development phase of TBFs.