In today‟s times, there has been an increasing interest in researching and inventing new antimicrobial agents from various foundations to battle microbial resistance. Therefore, a better consideration has been paid to antimicrobial activity screening and appraising methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cytofluorometric and bioluminescent methods are not widely used because they require specified equipment and further evaluation for reproducibility and standardization, even if they can provide rapid results of the antimicrobial agent's effects and a better acceptance of their impact on the viability and cell damage inflicted to the tested microorganism. This article discussed the various types of antibacterial assay available.