<p>Molecular chaperones are an integral part of the proteostasis network of the cell that regulate client protein folding, substrate interactions, disaggregation, degradation, and intracellular trafficking, either independently or through coordinated action with co-chaperones. Among them, heat shock proteins have emerged as key players in cancer, largely owing to their ability to stabilize oncogenic proteins and support tumor initiation and malignant progression. Their expression is dysregulated in cancer cells and secreted into circulatory system as a consequence of oncogenic signaling pathways. Because of these properties, molecular chaperones, particularly heat shock proteins have gained traction as potential biomarkers for cancer detection, including in point-of-care diagnostic applications. However, as heat shock proteins are involved in basal cellular activities, their levels are perturbed in several other benign cellular conditions. This review highlights the multifaceted roles of molecular chaperones, with a focus on heat shock proteins, in cancer development and progression. It further discusses recent advances and perspectives on major heat shock proteins as biomarkers for cancer diagnosis, emphasizing their potential to improve diagnostic accuracy. Additionally, this review addresses current challenges and limitations associated with the diagnostic use of heat shock proteins, providing insights to guide future research and clinical translation.</p>