Pyogenic liver abscess (PLA) is an uncommon but potentially lethal disease affecting humans worldwide. Despite the improvement in diagnostic imaging techniques and therapeutic modalities, the case fatality rate of PLA in patients with an underlying malignancy is high. There is little microbiological data available regarding PLA in patients with cancer. We found that the single most common organism isolated from PLAs was Escherichia coli (26.31%), followed by Enterococcus faecium (10.52%) and Pseudomonas aeruginosa (10.52%). More than half the cases were polymicrobial (20/38, 52.63%). Our data suggest that polymicrobial PLAs are common in patients with cancer. Further information is needed to determine how these trends might optimize prevention and treatment strategies for PLA in patients with cancer.