Protein mimotopes or blocking peptides are small therapeutic peptides that prevent protein-protein interactions by selectively mimicking a native binding domain. Inexpensive technology facilitates straightforward design and production of blocking peptides in sufficient quantities to undertake preventive and therapeutic trials in both in vitro and in vivo experimental disease models. The kidney is an ideal peptide target since small molecules undergo rapid filtration and efficient bulk absorption by tubular epithelial cells. Compared to the blood stream, the half-life of peptides in the kidney is markedly prolonged, making blocking peptides an attractive tool for treating diverse renal diseases including ischemia, proteinuric states such as membranous glomerulonephritis (MGN) and focal and segmental glomerulosclerosis (FSGS) or renal cell carcinoma. Therapeutic peptides represent one of the fastest growing reagents classes for novel drug development in human disease partly due their ease of administration, high binding affinity and minimal off target effects. This review introduces the concepts of blocking peptide design, production, and administration and highlights the potential use of therapeutic peptides to prevent or treat specific renal diseases.