Clonal variations were observed in pollen germination studies of six clones of Hevea brasiliensis viz. RRII 118, RRIM 600, PB 235, PB 255, PB 280 and KRS 128 for pollen size, stainability, germination percentage, mode of germination, pollen tube length and breadth. Largest pollen was observed in PB 255 (40.63 x 31.82 mm) and smallest in KRS 128 (37.35 x 30.75 mm). The highest pollen stainability (92.74;) and germination (51.19;) was recorded in RRII 118. The lowest germination was noticed in PB 280 (25.73;), which also registered the maximum pollen tube length (165.23mm). The highest pollen tube breadth was observed in PB 255 (13.24mm). Several abnormalities such as deformed pollen tube growth, development of more than one tube from a single pore and pollen tube branching were noticed in the clones Pb 280 and KRS 128.