To describe and interpret local antibiograms from a single tertiary care center to monitor the trends of antimicrobial resistance (AMR) patterns and establish baseline data for further surveillance. Methods: We performed a retrospective descriptive review of antibiograms data between January 2010 and December 2015 from King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia. Results: A total of 51,491 isolates were identified, and most were gram-negative (76.2%). Escherichia coli was the most frequently isolated organism (36.8%), followed by Coagulase-negative Staphylococcus (28.4%) and Staphylococcus aureus (27.5%). The detection of antibiotic-resistant organisms, especially extended-spectrum beta-lactamase-producing Escherichia coli (31%-41%), increased over time. The sensitivity of Streptococcus pneumoniae to penicillin improved from 66% to 100% (p less than 0.001). Gram-negative isolates had excellent overall susceptibility to amikacin, variable susceptibility to piperacillin-tazobactam and carbapenems, and declining susceptibility to ceftazidime, ciprofloxacin, and cefepime. Conclusion: Streptococcus pneumoniae susceptibility to penicillin significantly improved over time, which might be because of the introduction of the pneumococcal vaccine. Conversely, the upward trend in resistant gram-negative organisms is worrisome and warrants the implementation of antimicrobial stewardship programs.