Background <p>Substance use disorders (SUDs) are chronic brain diseases characterized by compulsive use of legal or illegal substances despite harm. Although pharmacological and psychosocial interventions have advanced, relapse remains common. Understanding psychological factors such as frustration tolerance and readiness to change is essential for guiding culturally sensitive relapse‑prevention strategies.</p> Methods <p>A cross-sectional study was conducted among 288 Egyptian outpatients diagnosed with substance use disorders, predominantly involving opioids and hallucinogens, with most participants reporting polysubstance use (two to four substances). Validated tools assessed relapse risk (Stimulant Relapse Risk Scale), frustration tolerance (Frustration Discomfort Scale) and motivational readiness for change (Stages of Change Readiness and Treatment Eagerness Scale). Descriptive statistics and Pearson correlations examined associations among these constructs and socio‑demographic and clinical factors.</p> Results <p>High relapse risk correlated with emotionality issues (62.8%) and lack of negative expectancies (64.2%). Frustration tolerance was low, with entitlement (61.8%) and achievement (64.6%) most affected. Motivational readiness showed significant barriers, with ambivalence prevalent in high‑risk patients (49.3%). Relapse risk positively correlated with frustration intolerance (<i>r</i> = 0.482, 95% CI 0.39–0.57, <i>p</i> &lt; 0.001) and negatively correlated with motivational readiness (<i>r</i> = − 0.399, 95% CI − 0.49 to − 0.30, <i>p</i> &lt; 0.001). Motivational readiness inversely correlated with frustration intolerance (<i>r</i> = − 0.643, 95% CI − 0.71 to − 0.57, <i>p</i> &lt; 0.001).</p> Conclusions <p>Emotional dysregulation, low frustration tolerance and ambivalence are common among Egyptian patients with SUDs. Tailored interventions focusing on emotion regulation, enhancing frustration tolerance and strengthening motivation may support recovery and reduce relapse risk.</p>