Rationale: Mycobacteroides abscessus infections affect immunocompromised patients and those with underlying pulmonary disease. Conventional imaging cannot distinguish M. abscessus infections from underlying pulmonary disease or sterile inflammation, requiring invasive procedures for definitive diagnosis. Objective: We evaluated ¹¹C-para-aminobenzoic acid (¹¹C-PABA), a chemically identical radioanalog of PABA, to detect and localize infections due to M. abscessus. Methods: In vitro uptake assays were performed to test the metabolism and accumulation of PABA into M. abscessus reference and clinical isolates. Dynamic ¹¹C-PABA positron emission tomography (PET) was performed in a mouse model of M. abscessus pulmonary infection and in a patient with microbiologically-confirmed M. abscessus pulmonary infection (NCT05611905). Main Results: ¹¹C-PABA was intracellularly metabolized by M. abscessus to ¹¹C-7,8-dihydropteroate. Additionally, and the reference and all thirteen randomly chosen clinical isolates, including three resistant to trimethoprim-sulfamethoxazole, rapidly accumulated PABA. No PABA accumulation was noted by heat-inactivated bacteria or mammalian cells. Dynamic ¹¹C-PABA PET in a mouse model of M. abscessus pulmonary infection rapidly distinguished infection from sterile inflammation and also accurately monitored response to antibiotic treatment. Finally, dynamic ¹¹C-PABA PET in a 33-year-old female with cystic fibrosis and microbiologically confirmed M. abscessus pulmonary infection was safe and demonstrated significantly higher and sustained PET uptake in the affected lesions. Conclusions: ¹¹C-PABA PET is an innovative, clinically-translatable, noninvasive, bacteria-specific diagnostic to differentiate M. abscessus infections from underlying pulmonary disease in patients. This tool could also help in monitoring treatment responses and enable precision medicine approaches for patients with complicated infections. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).