Driven by developments as globalisation, innovative networked organisational forms and increased mobility of employees, companies are increasingly employing eCollaboration in different forms. Despite of the growing importance of eCollaboration there is little research regarding the impact of eCollaboration as well as guidelines how to successfully implement eCollaboration in companies. This paper provides a contribution, by assessing the impact of eCollaboration in companies based on case studies and a cross-case analysis.