Background: Pulmonary nocardiosis is a rare pulmonary infection with high morbidity and mortality. Limited real-world data on pulmonary nocardiosis patients are available from developing countries like Pakistan. Methods: This retrospective observational study was conducted at the Aga Khan University Hospital, Karachi, Pakistan, from August 2003 to June 2020. Demographics, immune status, underlying diseases, laboratory data, treatment, and outcomes of all nocardiosis patients were recorded in predesigned proforma. Results: Sixty-six patients with smear/culture-proven pulmonary nocardiosis were identified. Most patients (83.3%) were treated with trimethoprim-sulfamethoxazole alone or in combination with other medicines. The overall mortality rate in our study was 33.3% (n = 22/66). Factors significantly associated with mortality were respiratory failure (p < 0.001), raised procalcitonin levels (p = 0.01), concomitant fungal infections (p = 0.01), concomitant TB (p = 0.03), and patients on combination therapy (p < 0.001). Respiratory failure (odds ratio [OR] 46.94 [95% confidence intervals [CI]: 5.01–439.03] p < 0.001), concomitant fungal infection (OR 17.09 [95% CI: 1.47–197.88] p- = 0.02) and patients on combination therapy (OR 6.90 [95% CI: 1.23–38.61] p = 0.02) were also identified as independent risk factors for mortality on multivariate analysis. Conclusions: This study provides essential information on the clinical characteristics and risk factors, outcomes, and factors associated with mortality for pulmonary nocardial infections.