<p>Understanding the unique challenges faced by older adults with mental health problems and implementing strategies that promote mental well-being are essential. This quasi-experimental study aimed to compare mental health problems among older adults before, immediately after, and 1 month after receiving an integrated mental health promotion program using a mobile application. In total, 14 men and 46 women aged over 60 years were included. They were assigned to the experimental group that received the program or the control group that received usual care. Data were collected using demographic questionnaires and the Depression Anxiety Stress Scale-21. Mental health problems were then assessed before, immediately after, and 1 month after the experiment. The program’s effectiveness was analyzed using a repeated measures t-test. Results showed that mental health problem scores significantly decreased among older adults immediately after and 1 month after the experiment. When compared over time and with the control group, the experimental group’s scores decreased significantly (<i>p</i> &lt; .05). Therefore, the integrated mental health promotion program combined with mobile application use can help older adults improve their mental health problems on their own. Mental health professionals can apply this program to reduce depression, stress, and anxiety among older adults in other settings.</p>