PurposeTo determine which proxy institutional quality variables are most significant for a country’s economic growth, the paper aims to investigate the effect of institutional quality on economic growth in upper-middle-income African nations between 2002 and 2021.Design/methodology/approachIn an attempt to account for countries' heterogeneity, the study uses a random and fixed effect model estimated by the generalized least squares.FindingsThe empirical findings demonstrate that the institutional quality measures of political stability, voice and accountability, corruption control and violence absence are statistically and favorably significant factors influencing the economic growth of upper-middle-income African countries.Originality/valueThis paper is unique in that it uses both random and fixed effects models to determine the effect of institutional quality on economic growth in the context of upper-middle-income African countries between 2002 and 2021.