Between December 1962 and May 1979, growth of choroidal and ciliary body melanomas was documented in 34 patients prior to enucleation, and in one patient whose eye was obtained at autopsy. Melanoma growth rates in 33 of these 35 eyes were calculated and compared with mitotic index, tumor cytology, tumor size, and mortality. Each melanoma appeared to grow at a constant rate that varied widely in different melanomas. Growth rate correlated with mitotic index. Most large tumors and epithelioid and mixed cell melanomas demonstrated fast growth rates. Most melanomas causing death contained epithelioid cells and were growing rapidly. These findings do not support the conclusion of Zimmerman and colleagues that enucleation is responsible for most metastatic deaths. Rather, it argues against one of the fundamental assumptions on which their conclusion is based, namely, that all melanomas have a relatively uniform slow growth rate prior to enucleation.