There is increasing evidence on the association of chronic bacterial infections with development of various types of cancers. Bacterial infections are involved in the processes and mechanisms leading to chronic inflammations, these are shown to cause molecular genomic damage and alterations which lead to transformation of normal cells to malignant cells. Moreover carcinogenic bacterial metabolites and toxins were found associated with development of various types of cancers. Furthermore recent findings are relating specific bacterial infections and inflammations with aberration of genomic DNA methylation. This article reviews various aspects which link chronic bacterial infections with chronic inflammations, development of cancers and their influence on aberration of genomic DNA methylation.