Isomerization of olefins with R3SnH–Et3B (R = Ph or n-Bu) system has been studied. Treatment of (Z)-1-triphenylstannyl-1-octene (1) or (E)-1-triphenylstannyl-1-octene (2) with a catalytic amount of Ph3SnH–Et3B provided an equilibrium mixture of 1/2 = 2/8. Partial isomerization was observed in the reaction of trivial alkenes such as 6-dodecene and 2,2-dimethyl-3-dodecene with R3SnH–Et3B system. Whereas