The significant contribution of small and medium-sized enterprises (SMEs) to job creation and economic growth has motivated a large body of research on the drivers of these firms’ performance. However, to date, limited empirical literature has examined the effects of the business environment (defined in terms of macroeconomic conditions) on SME performance in general, but particularly within a holistic multivariate approach which includes other key determinants. We address this gap by developing an integrated model which relates SME growth (in employment, turnover and productivity) to three sets of internal (firm characteristics - such as size and location - and firm strategy) and external (macroeconomic) factors. Multiple firm growth measures are employed to allow for the multidimensionality of firm performance. Using a large panel data set for manufacturing SMEs in Ireland during the period 1991-2007 and System Generalised Method of Moments estimations, this paper provides empirical evidence on the factors influencing SME performance and the channels through which this occurs. We contribute to the literature on contingent conditions for firm growth by providing empirical evidence that the importance of firm strategy for SME growth depends on prevailing macroeconomic conditions. Interestingly, we find that the changes in the drivers of macroeconomic growth, in our sample period, were reflected in differences in the effect of the determinants of SME performance. Similarly, the definition of firm performance used is important, with the effect of the macroeconomic environment and other firm-level determinants being sensitive to how performance is measured. Additionally, we observe that the firm’s starting quality, in terms of initial productivity and size, is critical to its subsequent performance.