Theoretical analysis of Poly-(L)-Lactic Acid (PLLA) nanofibers is a necessary step towards designing novel biomedical applications. This paper aims to analyze the mechanical properties of PLLA nanofibers so that optimal scaffolds in tissue engineering applications can be developed. We carry out analysis of PLLA nanofibers to estimate the mechanical properties from basic building blocks to the nanofibrous structures. A single PLLA nanofiber is made up of Shish-Kebab like fibrils intertwined together and can contain both amorphous and crystalline phases. The elastic modulus of the Lactic acid monomeric formation in the crystalline phase is derived using second-derivative of the strain energy using molecular dynamics simulation. The mechanical property of the Shish-Kebab fibril is derived by homogenization. The fiber modulus is then obtained using the Northolt and van der Hout's continuous chain theory. One of the significant contributions in this paper is the use of modified continuous chain theory, where a combined multiscale approach is used in the estimation of the mechanical properties of PLLA nanofibers. The theoretical results correlate well with reported experimental data.