A study was conducted to investigate the growth of gold (Au) on semiconductor rod heterostructures and on CdSe seeded CdS rods. It was found that these high-quality nanorod heterostructures exhibit significant optical properties that can be adjusted more controllably, as compared with one component systems. It was also found that Au growth is selective to the position of the CdSe seed, without producing defect sites. This behavior was assigned to an electrochemical Ostwald ripening process, where the seed is a sink for electrons, promoting Au growth in that region. It was demonstrated that the selectively located large gold dot on the rod may serve several purposes, such as a seed for growth of other semiconductor structures and an anchor point for self-assembly. The study also investigated the growth of Au on seeded rods with different dimensions.