This document discusses a protocol for a systematic review that aims to synthesize evidence on the relative risk of mortality in type 2 diabetes mellitus (T2DM). It provides background on the prevalence of T2DM and discusses inconsistencies in reported mortality rates. The systematic review will explore all-cause mortality risk in T2DM expressed as hazard ratios, and examine subgroups based on age, gender, socioeconomic factors and causes of death. The review expects to pool data from large cohort studies to accurately summarize the actual mortality risk in T2DM with limited bias and help direct future research.