Platelets play a pivotal role in hemostasis and thrombosis, serving as essential mediators of vascular integrity. Beyond their traditional functions, platelets are key contributors to various pathological processes, including inflammation, immune response modulation, wound healing, tumor growth, and metastasis. Platelet adhesion and aggregation occur in arteries, veins, and microvessels on disrupted or intact endothelial surfaces, constituting the innermost lining of blood vessels. These events are central to maintaining hemostasis and are pivotal in pathological conditions such as arterial thrombosis, venous thrombosis, and microvascular occlusions. Their multifaceted roles highlight the importance of platelets in both physiological and disease contexts, making them a critical focus of research in vascular biology and systemic pathologies. Microscopic imaging techniques in vivo have emerged as indispensable tools for studying platelet biology at high resolution and in real time. This chapter comprehensively overviews commonly used intravital microscopy models of in vivo platelet imaging, including but not limited to the study of platelet activation, recruitment to the injured vessel wall, aggregation, heterotypic-cellular interaction, and vessel occlusion in thrombosis and hemostasis in various vessels. The strengths and limitations of models and core components of an intravital microscope are also discussed. We have provided examples of studies conducted using each model to illustrate how in vivo platelet imaging has advanced our understanding of the role of platelet function in hemostasis and thrombosis while also guiding the development of novel platelet therapeutics. This chapter outlines in vivo platelet imaging techniques and aims to equip researchers with the knowledge to effectively utilize intravital microscopy in platelet research.