The Mannich reaction is a three-component condensation reaction involving an active hydrogen containing compound, formaldehyde and a primary or a secondary amine. The Mannich reaction is one of the most important basic reaction types in organic chemistry. This kind of aminoalkylation is important for the synthesis and modification of biologically active compounds. Many studies have shown that Mannich bases possesses potent biological activities: antibacterial, antifungal, anti-inflammatory and antimalarial properties. Mannich bases – substituted products containing different heterocyclic moiety in their structures seem to be suitable candidates for further chemical modifications and might be of interest as pharmacologically active compounds. The main goal of this article is to present synthesis and antimicrobial activity of selected Mannich bases. The Mannich reaction is known to be very useful for the synthesis of antibacterial compounds. The Mannich bases, containing various heterocyclic systems were identified as potent antimicrobial agents. Obtained in Mannich reaction derivatives of antibacterial drugs: ciprofloxacine, norfloxacine demonstrate higher antibacterial activity than used drugs, while derivatives of drugs: ibuporofen or phenytoine changed the profile of action of new synthesized compounds.