The Indian Ocean island nation's earnings from exports fell 17 percent to 6.86 billion rupees, its official statistics office said in a statement.
Sales of machinery and transport equipment declined to 687 million rupees from 1.34 billion a year earlier.
The statistics agency said total imports fell 5.1 percent to 15.02 billion rupees.
France was the main destination for Mauritius's exports in July accounting for 12 percent while India was its main supplier with 19.6 percent.