β-Lactams are the most widely prescribed antibiotics used for the control and treatment of bacterial infections. The direct effect of β-lactams on bacteria is well studied worldwide. In the context of infections and as a consequence of their direct activity against the pathogen, β-lactams also regulate antibacterial immune responses. This knowledge has led to the theorem that the effectiveness of β-lactam treatment results from the synergy between the drug and the immune response. Key players in this immune response, with an essential role in the clearance of live and dead bacteria, are the myeloid cells. In this review, we summarize the data that shed light on how β-lactams interact with myeloid cells during bacterial infection treatment.