Smishing, a rising phishing threat via SMS, affects millions of mobile users and businesses annually. It employs psychological persuasion techniques to deceive users into downloading malware and disclosing sensitive information, rendering victims vulnerable to social and financial exploitation. Research on phishing has typically focused on emails and social networks. However, despite its increasing prevalence, smishing remains understudied. In this research-in-progress, we aim to address this gap by building on Cognitive Dissonance Phishing Persuasion Theory and present an experimental study that will explore users’ cognitive and emotional responses to the most prevalent persuasion techniques in practice. We hypothesize that certain phrases (e.g., limited offers) and persuasion techniques (e.g., scarcity) will elicit distinct user responses (e.g., cognitive load, technostress) that render users more vulnerable to smishing. Employing eye-tracking, pupillometry, EEG, and EDA, this study pioneers the investigation of users’ neurophysiological responses to smishing, enhancing our understanding of phishing within the SMS domain.