The Home or Hospital in Heart failure (HHH) study was a European Community-funded, multinational, randomized controlled clinical trial, conducted in the UK, Poland, and Italy, to assess the feasibility of a new system of home telemonitoring (HT). The HT system was used to monitor clinical and physiological parameters, and its effectiveness (compared with usual care) in reducing cardiac events in heart failure (HF) patients was evaluated. Measurements were patient-managed. From 2002 to 2004, 461 HF patients (age 60 +/- 11 years, New York Heart Association class 2.4 +/- 0.6, left ventricular ejection fraction 29 +/- 7%) were enrolled at 11 centres and randomized (1:2) to either usual outpatient care or HT administered as three randomized strategies: (i) monthly telephone contact; (ii) strategy 1 plus weekly transmission of vital signs; and (iii) strategy 2 plus monthly 24 h recording of cardiorespiratory activity. Patients completed 81% of vital signs transmissions, as well as 92% of cardiorespiratory recordings. Over a 12-month follow-up, there was no significant effect of HT in reducing bed-days occupancy for HF or cardiac death plus HF hospitalization. Post hoc analysis revealed a heterogeneous effect of HT in the three countries with a trend towards a reduction of events in Italy. Home or Hospital in Heart failure indicates that self-managed HT of clinical and physiological parameters is feasible in HF patients, with surprisingly high compliance. Whether HT contributes to a reduction of cardiac events requires further investigation.