CTDs—such as SSc and SLE and related rheumatic diseases such as RA—have complex, underlying pathogeneses that include fibrosis, vascular dysfunction, activation of the immune system and inflammation. Although some current therapies for SSc offer benefits to patients, there is a clear need to investigate potential therapeutic targets. However, the breadth and diversity of cellular pathways and mediators implicated in these diseases, coupled with inherent redundancies in these systems, has made pre-clinical investigation difficult. Despite this, recent advances have been made in elucidating the immunological aspects of CTD, including the roles of B cells, T cells, matrix-remodelling cells and autoantibodies, enabling novel therapeutic approaches including immunoablation to be investigated. The mechanisms underlying the fibrosis that characterizes SSc are also becoming clearer; and as the putative events that trigger excessive collagen deposition are identified, so too are potential junctures at which these aberrant processes may be deactivated. Progress is also being made in understanding the vasculopathy in SSc, and the potential benefits of antioxidants and endothelin receptor antagonists. There have been some significant advances in the treatments available to SSc patients; however, this spectrum of diseases remains challenging, and continues in some cases to be associated with high morbidity, increased mortality and poor prognosis.