The molecular structure of octafluorobicyclo[2.2.0]hex-1(4)-ene has been measured in the gas phase by electron diffraction at room-temperature aided by results from molecular orbital theory. The results are consistent with D-2h symmetry for the molecule. The bond distances (r(g)/Angstrom) and bond angles (angle(alpha)/deg) with estimates of 2sigma uncertainties are r(C-1=C-4) = 1.376(14), r(C-1-C-2) = 1.530(3), r(C-2-C-3) = 1.627(5), r(C-F) = 1.336(2), and angle(F-C-F) = 108.6(3). The planes of the -CF2 groups are tipped away from the bisector of the C-C-C angle toward each other by about 2.8degrees. The measured length of the C-2-C-3 bond is even greater than the lengths of the structurally similar bonds in hexafluorocyclobutene and 1,2-dichloro-3,3,4,4-tetrafluoro-cyclobutene and agrees with prediction from quantum-mechanical structure optimizations at the B3LYP, B3PW91, and MP2 levels of theory. This and other features of the structure are discussed in terms of the bond-altering effects of electrostatic repulsions and rehybridization arising from electronegativity differences.