As a low molecular weight redox protein was elaborated from the pathogenic bacteria Pseudomonas aeruginosa, azurin is one of the representative bacterial products used in the treatment of tumours. In this study, Pseudomonas aeruginosa was isolated from lungs of cystic fibrosis patients in Egypt, and identified by 16S rRNA. Azurin gene was amplified using the suitable PCR programme. The gene was cloned into pGEM-T easy vector and sequenced. Then subcloned into the overexpression vector pET-28a (+) using E. coli BL21 as expression bacteria. The SDS-PAGE analysis showed that the gene overexpressed in E. coli. The recombinant protein was purified by one step purification using Ni^(++) resin. The effect of azurin on proliferation and apoptosis of human breast cancer cell line (MCF7), human hepatocellular carcinoma cell line (HEPG2) and human colon carcinoma cell line (HCT116) and human normal melanocytes (HFB4) cell line was studied. The results showed that azurin strongly inhibited the proliferation of both colon carcinoma cell line and breast cancer cell line. Whereas unclear result of the effect of azurin on hepatocellular carcinoma cell line was exhibited. At the same time, azurin didn’t show any effect on the human normal melanocytes.