**Background:** The use of traditional and complementary medicine (T&CM) is increasing in low- and middle-income countries, particularly for chronic diseases. In northern Uganda, the Acoli people experienced a prolonged armed conflict (1987–2006) that disrupted cultural practices, including traditional healing. This study aimed to understand how individuals become traditional health practitioners (THPs), perceived causes of illnesses, and diagnostic approaches among the Acoli in the post-conflict era.
**Methods:** This was a cross-sectional qualitative interview-based study conducted between January and June 2018 in eight districts of northern Uganda. Twenty-two THPs aged 39–80 years (median 59) were recruited through purposive and snowball sampling, using lists from the Acoli cultural institution (Ker Kwaro Acoli) and referrals from chiefs. Inclusion required being mentioned by at least two independent sources. Semi-structured in-depth interviews (60–120 minutes) were conducted in Acoli language, audio-recorded, and transcribed verbatim. Thematic analysis was performed using ATLAS.ti version 9.2, with codes developed independently by two researchers and refined by consensus.
**Key Results:** Three main themes emerged:
1. **Becoming a THP:** Most respondents reported that healing powers are acquired through inheritance from parents/grandparents (often without ritual), transfer after an unusual illness episode (with ritual and payment in kind), visions/dreams, or spirit possession during the ‘wero jok’ ritual. The transfer ritual requires a white, spotless chicken or goat to signify purity.
2. **Perceived causes of illnesses:** Multiple interacting factors were identified: fate/natural causes, spirit attacks (especially by disgruntled dead), curses from elders, witchcraft, contagion/infections (including sexually transmitted infections), poor hygiene, heredity/genetics, poisons, malevolent actions, poor diet (linked to cancers, diabetes, hypertension), and abrogation of cultural norms.
3. **Diagnostic approaches:** THPs use symptom/sign analysis, consultation with spirits (via diviners), observation of patterns/events, use of objects (e.g., cowry shells, special shoes, animal bones), diagnostic rituals (e.g., gut signs from goats/chickens), and referral for biomedical laboratory tests when illnesses are unfamiliar or considered ‘modern’ (e.g., cancers, hypertension, diabetes).
**Clinical Implications:** The study highlights that THPs in northern Uganda have structured pathways for acquiring healing knowledge and power, which can inform registration and licensing processes to ensure patient safety. Understanding THPs’ perceptions of illness causation and diagnostic methods is crucial for developing collaborative or integrative strategies between the national biomedical health system and traditional health practices. The findings also underscore the importance of culturally sensitive health interventions that address both biomedical and traditional explanatory models, particularly in post-conflict settings where cultural practices have been disrupted.