Introduction: Our article offers a deeper insight into an important occupational disease — coal workers’ pneumoconiosis, with all its diagnosis difficulties, treatment steps, and strategies. Case presentation: A 33-year-old male patient, smoker, with 16 years of outside exposure to coal dust, presents shortness of breath and cough, which existed 4 months prior to presentation and progressed in time. The first chest X-ray has raised differential diagnosis difficulties with miliary tuberculosis, despite the patient’s exposure history. All the investigation procedures performed afterwards (clinical examination, fibrobronchoscopy with microlavage and cytological examination, chest computed tomography, and routine laboratory investigations) were not enough to provide a certain and final diagnosis. Exploratory thoracotomy with lung biopsy was needed, and its findings started to sustain the professional disease diagnosis that had already taken shape. To exclude a disease which can evolve hand in hand, but also as a therapeutic application, we decided that a whole lung lavage was needed. Conclusion: Although whole lung lavage could not be accomplished completely, the performed right middle lobe bronchoalveolar lavage had a huge impact, not only on the patient’s symptomatology, but also on the paraclinical results.