OBJECTIVES: New drugs for treatment of Type 2 Diabetes mellitus (T2DM) are been approved, however, studies comparing the availability and characteristics of these drugs in different countries are lacking. The objective of this study was to examine the availability and characteristics of T2DM drugs approved in Canada, the US, and the UK in the period (1958-2015). METHODS: Regulatory data, including approvals, indications, contraindications, strengths, formulations, and approval dates of T2DM drugs were collected from US Food and Drug Administration (FDA), Health Canada (HC) and the UK Medicines and Healthcare Products Regulatory Agency (MHRA) websites. Descriptive statistics and t-tests were used in the analysis. RESULTS: In total, 29 drugs included in the study period. The FDA approved 27 (93.1%) T2DM drugs, HC 26 (89.7%) and UK 23 (79.3%). There were 7 (24.1%) T2DM drugs discontinued by the FDA, HC or MHRA. The comparative analysis included 18 T2DM drugs approved by the three agencies. T2DM drugs were first approved by the FDA (61.1%), MHRA (33.3%), and HC (5.65%). There was no significant difference between the average number of indications per T2DM drug approved by HC (1.81 ± 0.40), the FDA (1.19 ± 0.40) and MHRA (1.75 ± 0.58). The average number of contraindications was higher for T2DM drugs approved by MHRA (3.44 ± 3.14), followed by HC (3.22 ± 1.86) and the FDA (2.16 ± 1.04). More strengths per drug were available for T2DM drugs approved in the US (mean,2.72) than in the UK (mean, 2.27) and Canada (mean, 2.11). CONCLUSIONS: This study found significant differences in the availability and characteristics of T2DM drugs approved by HC, the FDA and MHA. More studies assessing the reasons and effects in clinical practice of differences in availability and characteristics of T2DM drugs in Canada, the US, and the UK three countries are needed.