Background <p>Covid-19 pandemic and its following lock-down lead to loneliness of older adults especially females. Smart phones can reduce the crises-caused complications. Technophobia is an overwhelming fear of technology or the powers of artificial intelligence.</p> Aims <p>The study focused on determining the impact of regular smartphone use in decreasing Technophobia and improving mental health and successful ageing (SA) for older adults residing alone during the Covid-19 pandemic.</p> Materials &amp; Methods <p>In this randomized controlled trial, 80 old females living alone as the member of a daily caring center were randomly categorized into intervention (40 people) and control (40 people) groups. The intervention group received 9 skill training online sessions of using smart phone through WhatsApp. The data were collected before and two months after intervention by demographic, Technophobia, Ryff’s Psychological Wellbeing (PW), and Successful Ageing Index. The data were analyzed by SPSS (V.28) through independent and paired t-tests and effect size measures.</p> Results <p>The results showed negative (r = 0.303) and significant (P &lt; 0.05) correlation between Technophobia and PW of old women living alone. Also, there were negative (r = 0.644) and significant (P &lt; 0.001) correlation between Technophobia and SA. The findings revealed no significant differences between the two studied groups based on Technophobia (r = 0.553), PW (<i>P</i> &gt; 0.05) and SA (<i>P</i> &gt; 0.05). However, there were significant differences between the two groups regarding the mean scores of Technophobia, PW, and SA in the two groups (P &lt; 0.001).</p> Discussion &amp; Conclusion <p>Online training of smart phone use is proposed to effectively reduce Technophobia and improve PW and successful ageing.</p> <p><i>Clinical Trials Registration</i> IRCT20180514039648N2, Registration Date: 25 July 2023.</p>