PurposeThis paper explores key factors influencing high-performing, sustained growth, high-tech small- and medium-sized enterprises (SMEs) in South Korea.Design/methodology/approachA qualitative study is adopted to explore seventeen founder owner-managers of high-tech SMEs who sustained consistent employment growth, greater than the industry average, for seven years. Within the sample, those with higher (10% or over) employment compound annual growth rates (CAGRs) over this period are also compared to those with lower rates.FindingsThe study suggests that proactive approaches, such as flexible organization, risk management, fast decision-making and international market entry, are seen as important contributing factors to sustained growth. These findings contribute to a better theoretical and empirical understanding of sustained high-tech SME growth, in a country with a strong entrepreneurial and internationally competitive information technology sector. Also, collaboration across the SME was perceived as making an important contribution to staff development and growth, consistent with stewardship theory.Research limitations/implicationsThe sample is based on successful high-tech SMEs, so there are limitations in extrapolating results to other types of firms, sectors or countries.Practical implicationsKey factors identified in this study can be considered by entrepreneurs seeking to achieve sustainable business. These also provide improved understanding for policymakers into the complexity of factors related to sustained and high growth of technology-based SMEs, which many countries are keen to foster to aid national economic growth.Originality/valueThe research provides new evidence exploring the diverse perspectives of founder owner-managers, on the sustained growth and failure in South Korean high-tech SMEs, and how these have changed since the inception of their business.