The study evaluates the effect of the global macro-economic business environment on the development of Small-Scale and Medium-Sized Enterprises (SMEs) in Nigeria. Secondary data on the global macro-economic index of SMEs businesses were selected over 35 years (1985–2019). The data collected were analysed using descriptive statistics and multiple regression analysis techniques. The study revealed the positive coefficient value of 354 836.6525 and 24 141 873.6 for the gross domestic product (GDP) on Purchasing Power Parity (PPP) and Budget variables. A negative coefficient value of –16347085.61 and –232997.0657 was obtained for the inflation rate and the exchange rate, respectively. The coefficient values show the level at which the development of SMEs businesses was affected through the global environmental factors. The study concluded that the global macro-economic business environment directly affects the development of SMEs businesses. The study recommends a policy strategy that will face out the global macro-economic constraints affecting SMEs businesses.