Pulmonary arterial hypertension (PAH) has devastating consequences in the rheumatic diseases; however, the prevalence in lupus is not well delineated. We searched the University of Toronto lupus database to ascertain the first echocardiogram ordered at their physician's discretion between 1995 and 2002. We reviewed the echocardiogram reports for right ventricular systolic pressure (RVSP), valvular disease, and atrial and ventricular function. The PAH was defined as RVSP > or = 40 mmHg. Patients were divided into three groups: RVSP > or = 40 mmHg, RVSP = 30-39 mmHg and RVSP < 30 mmHg. We analysed potential associations between presence of PAH and lupus including disease activity, organ involvement and anticardiolipin antibodies, both at the time of and any time prior to echocardiography. In total, 129 patients underwent echocardiography. Nine patients' echocardiograms were not obtainable, and three patients were excluded from analysis, as their visit was more than six months from the date of echocardiography. Sixteen patients (14%) had RVSP > or = 40 mmHg, 43 (37%) patients had RVSP of 30-39, and 60 (51%) patients had RVSP < 30 mmHg. There was no statistical difference in disease activity, organ involvement or serology among all three groups. In conclusion, the prevalence of PAH (RVSP > or = 40 mmHg) on first echocardiogram ordered at physician discretion in our cohort was 14%. An RVSP of 30-39 mmHg was found in 37% of patients. Although abnormal, the clinical significance of this finding is unknown. Disease activity, organ involvement and anticardiolipin antibodies were not associated with PAH. Further research is needed to identify the mechanism, response to immunosuppression and impact on quality of life in these patients.