Abstract: Background and Objective: Albezia lebbeck (Linn.) Benth. (Siris) is a significant legume tree chiefly planted throughout the world. Fusarium semitectum was both externally and internally seed-borne affecting seed germination, seedling vigour causing pre and post emergence mortality. Since, only few studies were available on the seed borne nature of F. semitectum. Therefore, the present study aims to elucidate the location of pathogen along with its transmission from seed to seedling. Materials and Methods: Fifty seven seed samples were collected from various locations of Jaipur and are subjected to dry seed examination. For evaluating the location of the pathogen seed were subjected to cleared whole mount preparation, handcut and microtome sectioning. During transmission studies the seeds of all category were tested through Standard Blotter Method (SBM), water agar seedling symptom test and pot experiments. Results: Albezzia lebbeck (Linn.) Benth. (Siris) seeds naturally infected with Fusarium semitectum showed either white mycelial crust (2.5-14.25%) and insect damaged (5.75-38.5%) causing wilt disease. These seeds on incubation yielded pure growth of the pathogen. Seeds were characterized as asymptomatic and symptomatic (weakly and heavily infected) on the basis of severity of infection. Cleared wholemount preparation and their section of seed revealed mycelial fragments in cells of seed coat of asymptomatic seeds and in symptomatic seeds pathogen invaded the deeper tissues of seed till the embryonal axis through the hilar tissue into the trachidial bars from where it densely spreads to embryonal axis, cotyledons and the space between two cotyledons. The pathogen is both externally and internally seed-borne. The internal innoculum affect seed germination, viability and caused high total (pre and post emergence) losses 35-85%. Conclusion: The pathogen is transmitted from seed to seedling causing heavy losses to the tree plantation. The pathogen was externally as well as internally seed-borne and internal inoculum affects seed germination, viability and elevated pre and post emergence losses.