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This work reports the observation of an electric field induced predissociation of the B-state of iodine. An argon-laser-pumped c.w. dye laser was used to excite a specific vibrational level ($v\prime$) in the B-state. The predissociation rate was related to the modulation of the resulting fluorescence intensity by an applied electric field. The predissociation rate was determined for the levels $v\prime =4$ to $v\prime =20$, working in a Nearly collision-free regime, with fields of the order of $1\times 104$ v/cm. Under these conditions the maximum rate was $5\times 102$ per second. The predissociation was interpreted to be due to field-induced mixing between the bound B-state and a repulsive state via an electric dipole operator. From symmetry considerations this repulsive state must be either a $0g+$ or $1g$ (in Hund’s case notation). Variation of the rate with $v\prime$ indicates that the crossing occurs between $v\prime =3$ and 4 on the outer limb of the B-state potential. Writing the rate in terms of Fermi’s ``Golden Rule’’ and using calculated Franck-Condon factors, the transition dipole was estimated to be $1.3\times 10-2$ debye. The results support the predictions of $Mulliken1$ and recent calculations of $Jaffe2$.