One of the fastest growing groups of portfolio workers is highly skilled independent professionals (IPros). Portfolio working is one way to remain agile in response to an increasingly dynamic labour market. Despite the rise of portfolio work globally, necessitating a deeper exploration of this contemporary form of employment, very little research has been conducted in this area. This study advanced our understanding of IPro employment by exploring key factors influencing their career motivations, choices, job satisfaction and desired organisational support. It used the conceptual lenses of protean and boundaryless careers and employed an exploratory sequential mixed methods research design utilising two phases. Phase I collected qualitative data through semi-structured interviews with a sample of casual teaching staff at a higher education institution in Australia. Phase II collected quantitative data from a sample of casual teaching staff from three higher education institutions (n = 206). The findings indicate that career decisions for IPros often involve a blend of free and forced choices influenced by personal aspirations and external market dynamics, along with a strong desire for autonomy and flexibility. These nuanced findings enrich our understanding of career agency in the modern workforce; policymakers in higher education can use these practical insights to manage and support their IPro staff more effectively. We recommend that HE institutions commit to managing the needs of IPros while integrating organisational expectations to deliver positive, sustainable outcomes for all.