Suicidal ideation among drug addicts is a critical concern, as addiction exacerbates mental health challenges and increases the likelihood of suicidal thoughts and behaviors. Drug addiction impairs problem-solving abilities, often leading to interpersonal conflicts. Unresolved conflicts can intensify isolation and raise the risk of suicidal ideation. This study quantitatively assesses the prevalence of interpersonal conflict among drug addicts in Malaysian rehabilitation centers, exploring its relationship with suicidal ideation. A cross-sectional approach was employed, with data collected from a sample of 123 drug addicts aged 26 to 55 years in a Malaysian rehabilitation center. Participants completed assessments using the Suicidal Ideation Behavior Assessment (SIBA), focusing exclusively on its interpersonal conflict component. The findings indicate that the level of interpersonal conflict among drug addicts is significant and closely associated with age and educational level. The average interpersonal conflict score is high, reflecting notable social relationship issues within this group. Significant associations between interpersonal conflict and age (t = -5.432, p = 0.002) as well as educational level (t = -4.321, p = 0.010) reveal that younger and less-educated individuals tend to experience higher levels of interpersonal conflict. Most participants experienced low (51.22%) or moderate (21.14%) conflict, with fewer reporting high (4.88%) or very high (0.81%) levels. The findings highlight the importance of addressing interpersonal conflict as a key factor in addiction rehabilitation. Early detection and targeted interventions for younger, less-educated individuals are key to reducing suicidal ideation and improving well-being among drug addicts. Conflict resolution and relationship-focused strategies are essential for effective rehabilitation.