The present work pertains to kinetic behavior and mechanism of hydrolysis of sec-amyl iodide. In the kinetic study of alkaline hydrolysis of sec-amyl iodide, it has been observed that four simultaneous, recognizably distinct reactions are occurring together. Two of these reactions are second order processes, while other two of them are first order processes, each with respect to halide. The base employed was NaOH. Solvent effect on the kinetics of sec-amyl iodide has been investigated in alkaline and neutral medium in[EtOH-H2O] mixture up to 60% v/v in the temperature range of 400C-750C in alkaline and 500C in neutral media respectively. The velocity in the first order process depends upon the concentration of halide molecule (i.e. sec-amyl iodide). In absence of NaOH the first order process alone occurs and it has been observed that the rate of the first order process and the velocity of first order processes increase with the increase in the dielectric constant of the medium. The rate expression can be written as : [ ] K [RX][OH ] K' [RX] dt d RX 2 1 - = - + . Activation parameters were also determined.