Introduction: Opportunistic bacterial and fungal infections are the major cause of morbidity and mortality among immune suppressed HIV-positive patients. The main objective of this study was to determine bacterial and fungal organisms causing respiratory infections and their susceptibility to commonly prescribed antimicrobials among HIV patients attending a tertiary infectious disease hospital in Kathmandu. Methods: Sputum samples were collected from the HIV-positive patients attending Sukraraj Tropical and Infectious Disease Hospital (STIDH) from August 2017 to March 2018. A total of 100 sputum samples were cultured on conventional bacterial and fungal culture media. Bacterial and fungal isolates were identified based on their colony characteristics, microscopic morphology and various biochemical tests. Antibiotic susceptibility test (AST) of bacterial isolates was performed by modified Kirby Bauer disc diffusion method. Results: Out of 100 sputum samples cultured, 24% (n=24) showed bacterial growth, 42% (n=42) showed fungal growth and 10% (n=10) had both bacterial and fungal growth. Among bacteria, 91.6% (n=22) were monomicrobial and 8.4% (n=2) were polymicrobial in growth, of which, Klebsiella pneumoniae (37.5%) were predominant isolates, followed by Pseudomonas aeruginosa (29.2%), and Escherichia coli (16.7%). The antibiotic susceptibility test (AST) showed 68% (17/25) of bacterial isolates were multi-drug resistant (MDR) and among them 41.2% (7/17) were found to be extended spectrum β lactamase (ESBL) producers. Fungal growth was observed in 42% of samples (42/100). A total of six different species of Candida and four different genera of molds were identified. On species differentiation, Candida albicans (20%) were followed by Candida parapsilosis (4%), and Candida dubliniensis (3%); and various molds were Aspergillus fumigatus (4%), Aspergillus flavus (2%), and Penicillium species (5%). CD4 count was inversely associated with bacterial and fungal infections. Fifty percent of the patients with the fungal infections had a CD4 count below 200. No fungal organisms were isolated from HIV-positive patients under antifungal drug treatment. Conclusion: HIV-positive patients with a CD4 count less than 200 cells/µL are more vulnerable to opportunistic infections of bacterial and fungal origin. Early isolation, identification and appropriate treatment can reduce mortality due to co-infections. Routine screening of opportunistic pathogens is critical to contain the disease progression.