The Gram-positive and Gram-negative bacteria are attributable to matrix-enclosed aggregates known as biofilms. Biofilms are root cause of industrial biofouling and characterized by antimicrobial resistance during infections. Many biofilm studies examine specific Gram type cultures, whereas nearly all biofilm communities in nature comprise both Gram-negative and Gram-positive bacteria. Thus, a greater understanding of the conserved themes in biofilm formation is required for common therapeutics. We tried to focus on common components which exist at each stage of biofilm development and regulation. The Lipopolysaccharides (LPS) and cell wall glyco-polymers of Gram-negative and Gram-positive bacteria seem to play similar roles during initial adhesion. The inhibition of the polymerization of amyloid-like proteins might impact the biofilms of both Gram-type bacteria. Enzymatic degradation of matrix components by glycoside hydrolase and DNase (nuclease) may disrupt both Gram-type biofilms. An additional common feature is the presence of membrane vesicles, and the potential of these vesicles requires further investigation. Genetic regulation by c-di-GMP is prominent in Gram-negative bacteria. However, quorum sensing (QS) may play a common regulation during biofilms dispersal. These studies are significant not only for common therapeutic against mixed biofilms, but for better understanding of bacterial interactions within natural or host infection environment as well.