This retrospective, multicentre study evaluated patients with lymphangioleiomyomatosis (LAM) and pre-capillary pulmonary hypertension (PH) by right heart catheterisation. It was conducted in 20 females with a mean ± SD age of 49 ± 12 yrs and a mean ± SD time interval between LAM and PH diagnoses of 9.2 ± 9.8 yrs. All, except for one patient, were receiving supplemental oxygen. 6-min walking distance was mean ± SD 340 ± 84 m. Haemodynamic characteristics were: mean pulmonary artery pressure (PAP) 32 ± 6 mmHg, cardiac index 3.5 ± 1.1 L · min(-1) · m(-2) and pulmonary vascular resistance (PVR) 376 ± 184 dyn · s · cm(-5). Mean PAP was >35 mmHg in only 20% of cases. The forced expiratory volume in 1 s was 42 ± 25%, carbon monoxide transfer factor was 29 ± 13%, and arterial oxygen tension (P(a,O(2))) was 7.4 ± 1.3 kPa in room air. Mean PAP and PVR did not correlate with P(a,O(2)). In six patients who received oral pulmonary arterial hypertension (PAH) therapy, the PAP decreased from 33 ± 9 mmHg to 24 ± 10 mmHg and the PVR decreased from 481 ± 188 dyn · s · cm(-5) to 280 ± 79 dyn · s · cm(-5). The overall probability of survival was 94% at 2 yrs. Pre-capillary PH of mild haemodynamic severity may occur in patients with LAM, even with mild pulmonary function impairment. PAH therapy might improve the haemodynamics in PH associated with LAM.