This study analyses the factors influencing environmental behaviours in Irelands’ biopharmaceutical industry employees utilising secondary research and qualitative primary research methods. The secondary research undertaken indicates that several factors positively impact environmental behaviours including convenience and belonging to a group with positive environmental intentions i.e. peer influence. Within an industry setting, a combination of factors is evident. This includes individual factors e.g. beliefs and environmental awareness, group factors e.g. feedback and financial incentive, organisational factors e.g. culture and management support and external factors e.g. actions at home and legislation. The primary research carried out with employees of 10 biopharmaceutical companies in Ireland shows that several individual, group, organisational and external factors impact the behaviours of employees, thereby reflecting the secondary research findings. The data shows that to optimise efforts a combination of these factors is required. However, company culture, infrastructure and regulation were found to be the most influential factors. Company culture improvements must move from a profit driven mindset, to improve environmental behaviour through voluntary corporate social responsibility. Research suggests a culture shift is a long-term change. In the short to medium term regulation and infrastructure changes are advised. Introducing requirements to align with positive environmental action through regulation drives companies to ensure compliance, as not doing so can affect release of product and lead to financial cost. Both infrastructure and regulation serve to make the positive environmental choice the most obvious. The presence of environmental infrastructure makes the choice easy resulting in employee cooperation. This research indicates that current efforts within the biopharmaceutical industry to ensure optimal environmental impact is moderate. Therefore, further work is required in this area to improve the effort of both the individual and the company and to lessen the environmental impact going forward. The findings of this study may be used within the biopharmaceutical and similar industries to analyse, promote and improve current efforts of ensuring positive environmental behaviour.