Retroviral vectors are a promising tool for gene therapy. However, there are two major problems to overcome if a viable commercial production process is to be established. These are the instability of virus particles and the low virus titres. The characteristics of the producer cells were determined in batch culture, semicontinuous culture and semi-continuous culture at 32°C. Additionally, cell attachment, growth and virus production on various macroporous microcarriers was assessed under static and stirred conditions. Alternative strategies for the cultivation of cells were also investigated. These included spinner basket, packed bed and spinner flask cultures with semi-continuous feeding and packed bed, fixed bed, fluidised bed and stirred tank cultures with continuous perfusion of culture medium. Of these the fixed bed bioreactor had the highest cell specific productivity and was capable of running for 28 days. The fluidised bed bioreactor had the highest reactor productivity, due to the higher cell number. Optimisation of culture medium was performed with regard to serum concentration. The greatest production was observed at an initial serum concentration of 2.5% (v/v). The findings in this thesis will assist the development of an efficient method for the production of clinical grade retro viral vectors for gene therapy applications.