This paper describes two different strategies to obtain stable beads of 1,4-polybutadiene (PB) by suspension ring-opening metathesis of 1,5-cyclooctadiene carried out in water. Both rest on the use of amphiphilic stabilizing agents whose hydrophilic/hydrophobic balance was finely tuned. A norbornenyl-ended poly(styrene-b-ethylene oxide) macromonomer and an in situ prepared poly(butadiene-g-ethylene oxide) graft copolymer provided the required stability for PB beads in the range of 20 mum to remain suspended in water.