2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/165537We study the issue of black hole entropy in the topologically massive gravity. Assuming that the presence of gravitational Chern-Simons term with the coupling $1/μ$ does modify the horizon radius $\tilde{r}_+$, we propose $\tilde{S}_{BH}=π\tilde{r}_+/2G_3$ as the Bekenstein-Hawking entropy. This entropy of CS-BTZ black hole satisfies the first-law of thermodynamics and the area-law but it is slightly different from the shifted-entropy $S_c=πr_+/2G_3+ (1/μl)πr_-/2G_3$ based on the BTZ black hole with outer $r_+$ and inner horizon $r_-$. In the case of $r_-=0$, $\tilde{S}_{BH}$ represents the entropy of non-rotating BTZ black hole with the Chern-Simons term (NBTZ-CS), while $S_c$ reduces to the entropy of NBTZ black hole. It shows that $\tilde{S}_{BH}$ may be a candidate for the entropy of the CS-BTZ black hole.11 pages, an expanded version to discuss thermodynamic aspects of BTZ-CS and CS-BTZ black holesHigh Energy Physics - Theorytext