This interpretive grounded theory (GT) study describes and analyses the lived experiences of project members who worked in a three year long inter-organisational information system (IOIS) project. The Inter-Organisational Information Systems (IOIS) project was a Nordic project which spanned four user organisations, two suppliers, one national organisation, a research organization and a Ministry who funded the project. The data was elicited by means of narrative stories, observations of project meetings, diaries, project memoranda and emails sent by project members to each other during these years. This study shows how GT can be used to gain significant insights into a case study, and generate new concepts. We identified Certainty, Significance, Connection and Contribution as important selective codes that make up the emotions category. This study shows that emotions have a remarkable role during the process of an IOIS. The paper concludes by discussing how certainty, significance, connection and contribution issues could be attributed to emotions and considers some theoretical and practical implications.