The increasing demand for skilled employees in contemporary economies underscores the importance of effective upskilling of the low-skilled. This study addresses the significant challenge of enhancing the professional development of low-skilled workers, focusing on the factors that either facilitate or hinder their engagement in learning activities. The primary aim was to identify the key characteristics that contribute to the effective professional development of low-skilled employees and the practical application of the skills they acquire. A systematic review was conducted, examining empirical studies published between 2004 and 2024. The search encompassed six databases, resulting in 352 identified articles. After rigorous screening and quality assessment, 22 high and good-quality studies (published in 2011-2023) were included in the final selection. The studies spanned various countries and methodologies, including qualitative, quantitative, and mixed-method designs. Key findings highlight that both personal and contextual factors influence the effectiveness of professional upskilling for low-skilled employees. Personal factors include motivation, self-direction, and reflexivity, while contextual factors encompass the quality of the work environment, learning opportunities, and institutional support. The review emphasises the importance of tailored training programmes, practical and interactive learning methods, continuous support and mentorship, and robust evaluation mechanisms. Effective transfer of training is facilitated by the relevance and applicability of training content, learner engagement and organisational support. The results highlight the need for holistic approaches that address both personal and contextual factors to enhance the professional development and skill utilisation of low-skilled workers; ultimately contributing to their career trajectories and job satisfaction.