Introduction: Tigecycline, the first agent of a new antibiotic class, the glicylcyclines, has been recently introduced in Colombia and there is no local data available regarding its in vitro activity. Objective: To evaluate in vitro activity of tigecycline on clinically relevant bacterial isolates from hospitalized patients in three institutions in Colombia. Methods: Aerobic and facultative anaerobic isolates from infections in inpatients from the three participant institutions were sent to a central referral laboratory to determine minimal inhibitory concentration (MIC) by microdilution broth method for tigecycline and other antimicrobials. Breakpoints for tigecycline and others antibiotics were adopted from the FDA and the CLSI recommendations, respectively. Results: In vitro susceptibility in percentage and MIC50/90 values were as follows: Staphylococcus aureus (n=78) 100%, 0.12/0.12 mg/L; Streptococcus pneumoniae (n=24) 100%, 0.015/0.5 mg/L; Streptococcus agalactiae (n=10) 100%, 0.03/0.06 mg/L; Enterococcus spp (n=43) 100%, 0.06/0.12 mg/L; Klebsiella pneumoniae (n=56) 96.4%, 0.5/1 mg/L; Klebsiella oxytoca (n=15) 93.3%, 0.25/2 mg/L; Escherichia coli (n=89) 100%, 0.12/0.5 mg/L; Enterobacter cloacae (n=48) 100%, 0.5/2 mg/L; Serratia marscescens (n=42) 96.2%, 0.5/2 mg/L. For Haemophilus influenza (n=15) and Acinetobacter baumannii (n=36), which still lack defined breakpoints, MIC50/90 were 0.06/0.12 and 0.5/2 mg/L, respectively. 100% of extended espectrum betalactamase producers of Escherichia coli (n=18) and 94.4% of those of Klebsiella pneumoniae (n=18) were susceptible to tigecycline. MIC50/90 for Pseudomonas aeruginosa (n=63) were 8/16 mg/L. Discussion: Tigecycline showed excellent in vitro activity against gram positive cocci and gram negative bacilli recovered from hospitalized patients in Colombia regardless of the presence of resistance to others antimicrobial agents.