The current era has seen a sharp increase in maladies in the form of diseases and infections that have negatively affected the health, standard of life, healthcare expenditure as well as mortality of the individual. Diagnosis of such diseases requires identifying the biomarker molecules that are specific for the infection or diseased condition. The rapid evolution of biosensors in the field of disease diagnosis has provided the medical fraternity with an advanced level of diagnostics having high sensitivity, specificity and reproducibility. Biomarkers that are present in very less amounts require a highly sensitive biosensor that can even detect its pico-molar quantities in the sample. Graphene owing to its exceptionally diverse functionalities has gained worldwide recognition for use as a biosensor. This chapter explores the current advancement of graphene-based biosensors in medical diagnostics and treatment by the detection of different biomarkers in the biological sample. Impetus has been given on various methods for the development of graphene-based biosensors. In addition, future challenges and prospects have been discussed that may provide research in the field of graphene biosensors in a more channelled way for exceedingly specific, sensitive and throughput detection of the emerging fatal diseases.