Dynamic imaging of transgenic quail expressing histone 2B‐YFP under the control of the Tie1 promoter allowed endocardial progenitor cells to be followed through time and space during avian tubular heart morphogenesis. Simultaneous imaging of the nearby cardiac jelly/extracellular matrix (ECM) was performed as an indicator of the relative tissue motion during tubular heart formation. Monoclonal antibodies to fibronectin, fibrillin‐2, and laminin were fluorochrome‐conjugated and microinjected into the splanchnopleura of transgenic avian embryos at HH 8, prior to tubular heart formation. Time‐lapse recording was conducted until HH12, when cardiac looping is underway. Endocardial precursor cells were observed streaming into the anterior and posterior cardiac poles, as well as traversing the floor of the foregut to enter the heart via the dorsal mesocardium. Simultaneously, ECM fibrils were recruited from extracardiac sources to form portions of the cardiac jelly. In some cases, endocardial cells were observed to travel on aligned ECM fibrils to enter the heart. Ongoing cellular and ECM tracking will allow computation of endocardial cell movements relative to the surrounding ECM to determine the extent of cell autonomous motility versus tissue‐level convection during tubular heart morphogenesis. Supported by NIH HL085694 and the Mathers Foundation.Grant Funding SourceSupported by NIH HL085694 and the Mathers Foundation.