Limited functional status is a common health problem in patients living with heart failure (HF), which often requires rehospitalization.Home-based transitional telehealth programs (TTPs) focused on health monitoring, education, promotion of self-management, and multidisciplinary team consultation have been shown to improve functional status and satisfaction with care while reducing rehospitalization rates in this population. Nonetheless, these variables and outcomes have yet to be assessed in a Thai patient with HF. Thus, the aim of this study was to investigate the effectiveness of a TTP on functional status, rehospitalization, and satisfaction with care in Thai patients with HF. Eligible participants (N = 146) were randomly assigned to either the control or TTP group. The TTP included in-hospital discharge planning and 6-week telemonitoring via a mobile phone application to provide follow-up home care. Data on the outcome variables were collected at 6 and 8 weeks post-enrollment and analyzed by descriptive statistics, independent t-tests, repeated measures ANOVA, and Z-tests. Functional status and satisfaction with care scores in the TTP group were significantly higher than those of the control group, and rehospitalization rates in the TTP group were significantly lower than those of the control group at 6 and 8 weeks post-enrollment. Thus, the TTP effectively improved functional status, increased satisfaction with care, and reduced rehospitalization rates in Thai patients with HF. TTP implementation could be considered to improve the quality of transitional care in Thailand.