The conformational changes of the backbone as well as the side chains of poly(di-n-hexylsilane) during the isothermal crystallization from the disordered phase was investigated. The backbone reorganization was detected by fluorescence and UV, while the side-chain reorganization was detected by IR. It was found that the backbone reorganization begins to occur prior to the side-chain reorganization. This trend is observed for all the crystallization temperatures investigated. At lower temperatures, the difference in the time of reorganization was not very large, but at higher temperatures the difference becomes larger.