Objective: Most individuals attending detoxification clinics do not pursue subsequent treatment. Earlier research has suggested that emerging technologies like mHealth interventions could address the postdetoxification treatment gap, yet it remains unclear whether patients themselves endorse such approaches. Our study aimed to qualitatively explore perceived treatment barriers and assessed potential of mHealth among individuals who have undergone alcohol detoxification. Method: We conducted a single-interview-per-participant qualitative study, sampling participants (n = 23) that had visited the Stockholm substance use disorder emergency department for alcohol-related reasons, of whom n = 8 were purposively included due to having missed their scheduled follow-up outpatient appointment. Semistructured telephone interviews were conducted (2021–2022) and then systematically analyzed using reflexive thematic analysis. Results: Across both areas of analysis, we identified six themes in total. We clustered barriers to postdetoxification treatment into three themes (10 subthemes) that may offer a nuancing perspective on previous research: “Misalignment between the treatment system and the individual,” “Practical hurdles” and “Between reaching out and retreating.” We identified three themes in participants’ perspectives on mHealth as aftercare support, revealing expectations that such an approach may promote “self-awareness on own terms,” assist in “navigating from solitary substance use struggles to supportive connections,” and “offer a lifeline when needed most,” thereby potentially resolving several barriers to treatment. Conclusions: This first qualitative study on barriers to alcohol treatment and mHealth potential postdetoxification offered various insights that may be translated into effective, real-world solutions to bridge the postdetoxification treatment gap. A natural next step for future research is to evaluate the impact of mHealth postdetoxification.