The developmental kinetics of cytoplasmic and chloroplastic ribosomal RNA (r-RNA) and chlorophyll in pea buds upon transfer from dark to light were investigated. A relationship was found between the light-dependent development of chloroplastic r-RNA and chlorophyll while cytoplasmic r-RNA showed no direct relationship to these two. Chloroplastic r-RNA showed no lag period in its rate of formation while chlorophyll showed a lag of 24 hr after initiation of the light. Inhibition studies with cycloheximide and chloramphenicol showed a parallel inhibition between chloroplastic r-RNA and chlorophyll. The constant relationship between these two components in the developing pea buds and the appearance of chloroplastic r-RNA before chlorophyll leads to the conclusion that there is a direct dependence of the production of chlorophyll on the amount and appearance of chloroplastic r-RNA. This supports the hypothesis that the enzymatic or structural proteins involved in chlorophyll production are formed on the chloroplast ribosomes.