Golden Star Proven and Probable Mineral Reserves as at December 31, 2017.

1. The stated Mineral Reserves have been prepared in accordance with the requirements of National Instrument (“NI”) 43-101 and are classified in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum’s “CIM Definition Standards – For Mineral Resources and Mineral Reserves”. Mineral Reserve estimates reflect the Company’s reasonable expectation that all necessary permits and approvals will be obtained and maintained. Mining dilution and mining recovery vary by deposit and have been applied in estimating the Mineral Reserves.
2. Mineral Reserves are the economic portion of the Measured and Indicated Mineral Resources. Mineral Reserve estimates include mining dilution at grades assumed to be zero.The slope angles of all pit designs are based on geotechnical criteria as established by external consultants. The shape and size of the pit designs are guided by consideration of the results from a pit optimization program.
3. The 2017 Mineral Reserves were prepared under the supervision of Dr. Martin Raffield, Senior Vice President Project Development and Technical Services for the Company. Dr. Raffield is a QP as defined by Canada’s NI 43-101.
4. The Mineral Reserves at December 31, 2017 were estimated using a gold price assumption of $1,250 per ounce.
5. The slope angles of all pit designs are based on geotechnical criteria as established by external consultants. The size and shape of the pit designs are guided by consideration of the results from a pit optimization program
6. Cut-off grades have been estimated based on operating cost projections, mining dilution and recovery, government royalty payment requirements and applicable metallurgical recovery. Marginal cut-off grade estimates for the open pits are as follows: Wassa 0.6 grams per tonne (“g/t”) of gold (“Au”); Mampon 1.3 g/t Au; and Prestea South 1.1 g/t Au. Break-even cut-off grade estimates for the underground mines are as follows: Wassa Underground 2.0 g/t Au; and Prestea Underground 6.5 g/t Au.
7. Numbers may not add due to rounding
8. Only non-refractory ore is included in Mineral Reserves.

Golden Star Measured and Indicated Mineral Resources as at December 31, 2017

1. All Measured and Indicated Mineral Resources in 2017 and 2016 estimates are in Indicated category.

Golden Star Inferred Mineral Resources as at April 6, 2018

Notes to Mineral Resource Estimates

1. The Mineral Resources for “Wassa Other” include Father Brown, Benso and Chichiwilli.
2. The Mineral Resources for “Bogoso/Prestea Others” include Chujah, Dumasi, Bogoso North, Buesichem, Opon, and Ablifa.
3. The Wassa Underground Mineral Resource has been estimated below the $1,450 per ounce of gold pit shell using an economic gold grade cut-off of 1.62 g/t Au, which the Company believes would be the lower cut-off grade for underground mining. And constrained to a 1.5 g/t Au mineralized grade shell
4. The Father Brown Underground Mineral Resource has been estimated below the $1,450 per ounce of gold pit shell using an economic gold grade cut-off of 2.84 g/t Au, which the Company believes would be the lower cut-off grade for underground mining.
5. Prestea Underground Mineral Resource has been estimated below the $1,450 per ounce pit shell of Prestea South down to 3,800 metres elevation using a gold cut-off grade at 5.50 g/t Au.
6. Mineral Resources were estimated using optimized pit shells at a gold price of $1,450 per ounce. Other than gold price, the same optimized pit shell and underground parameters and modifying factors used to determine the Mineral Reserves were used to determine the Mineral Resources.
7. Mineral Resources are inclusive of Mineral Reserves.
8. Numbers may not add correctly due to rounding.

Mr. S. Mitchel Wasel is a "Qualified Person" as defined by Canada's NI 43-101. Mineral Resources were prepared under the supervision of S. Mitchel Wasel, Vice President of Exploration for Golden Star.

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