The Sanskruti index of a graphGis defined as$$\begin{align*}S(G)=\sum_{uv\in{}E(G)}{\left(\frac{s_G(u)s_G(v)}{s_G(u)+s_G(v)-2}\right)}^3, \end{align*}$$wheresG(u) is the sum of the degrees of the neighbors of a vertexuinG. LetPn,Cn,SnandSn+ebe the path, cycle, star and star plus an edge ofnvertices, respectively. The Sanskruti index of a molecular graph of a compounds can model the bioactivity of compounds, has a strong correlation with entropy of octane isomers and its prediction power is higher than many existing topological descriptors.In this paper, we investigate the extremal trees and unicyclic graphs with respect to Sanskruti index. More precisely, we show that(1)$\frac{512}{27}n-\frac{172688}{3375}\leq{}S(T)\leq{}\frac{(n-1)^7}{8(n-2)^3}$for ann-vertex treeTwithn≤ 3, with equalities if and only ifT ≌Pn(left) andT≌Sn(right);(2)$ \frac{512}{27}n\leq{}S(G)\leq{}\frac{(n-3)(n+1)^3}{8}+\frac{3(n+1)^6}{8n^3}$for ann-vertex unicyclic graph withn≥ 4, with equalities if and only ifG ≌Cn(left) andG≌Sn+e(right).