We have discussed the design and development of mpiJava - a pure Java interface to MPI. We have also highlighted the benefits of a fully object-oriented Java API compared to those currently available. Our performance tests have shown that mpiJava should fulfil the needs of MPI programmers not only in terms of functionality but also in terms of good performance when compared to similar C MPI programs. Unfortunately, at the time of submission of this paper we have been unable to test mpiJava under Linux, but we believe that the problems we have encountered we be overcome soon and we will be able to present our finding during the Workshop in April 1999. Overall, however, we feel that we have implemented a well designed, functional and efficient Java interface to MPI.