According to the World Health Organization (WHO), stress-related chronic diseases are the main source of death in developed countries. During the last decade, e-mental health, telepsychology or telepsychiatry interventions are showing its growing potential due to the gradual global adoption of the internet and mobile phone technologies. A significant number of studies have concluded that mindfulness helps to reduce physical and psychological symptoms of stress related to various health concerns and that it is a psychological skill that can be trained. The purpose of this online research study is to gather the participants' socio-demographics as well as stress and mindfulness data during an online mindfulness training program. Sustained attention and the state of mindfulness experienced in single meditation sessions are also tracked and stored. Correlational analysis yielded to a statistically significant relationship between high scores in stress and low scores in mindfulness facets (p < .001) and between state and trait aspects of mindfulness (p < .01).