Renal medullary cystic diseases are a large class of heterogeneous diseases,and they are common in clinic,most of them often progress to end-stage renal disease.With recent advances in genetics,increasing number of genes and genetic mutations has been identified with the etiology of renal medullary cystic diseases.Although genetic testing can provide mass data for diagnosis,clinical manifestation are even more important for clinical diagnosis,differentiation and genetic counseling for the patients.In this review,the classification,renal presentations,extra-renal presentations,and genetic analysis of renal medullary cystic diseases will be discussed.