Introduction: Tigecycline has emerged as first line therapy for serious systemic infections due to important pathogens (except P. aeruginosa and Proteus sp.), including multi-drug resistant (MDR) and Gram negative bacilli (GNB), including carbapenem resistant Enterobacteriae. Tigecycline has a ‘low resistance potential,’ is protective against C. difficile, and is often the only antibiotic effective against MDR GNB, e.g., Klebsiella sp. Areas covered: Standard dose tigecycline therapy has been used for intra-abdominal infections, complicated skin/skin structure infections (cSSSIs), and CAP. Clinical experience with once daily high dose tigecycline (HDT), i.e., 200 – 400 mg (IV) x 1, then 100 – 200 mg (IV) q24 h, is reviewed. Optimal tigecycline efficacy is dependent on PK/PD based dosing. Suboptimal outcomes have been due to inappropriate use or suboptimal dosing. Expert commentary: Tigecycline’s spectrum against nearly all important pathogens (including MSSA/MRSA, VSE/VRE, B. fragilis, C. difficile, MDR and GNB) assures tigecycline a critical place in the antibiotic armamentarium. Dosed optimally, HDT can be a cornerstone of antibiotic stewardship programs in preventing C. difficile, treating MDR GNB pathogens, and in preventing resistance. Properly used and optimally dosed, once daily HDT should be considered preferred therapy for severe systemic infections and those due to MDR GNB pathogens.