We have studied polyacene within the Hubbard model to explore the effect of electrons correlations on the bond-bond correlation as well as spin-spin correlation functions. We employ the determinantal quantum Monte-Carlo to resolve the microscopic Hamiltonian of this system which involves a nearest-neighbor electron hopping matrix element t, an on-site Coulomb repulsion U. The objective of this study is to understand the effect of electron-electron (e-e) correlations on the structural instability in polyacene. We find strong similarities between polyacene and polyacetylene. The system shows no tendency to destroy the imposed bond-alternation pattern. The spin-spin correlations show that undistorted polyacene is susceptible to a spin-density wave distortion for large interaction strength (U). (C) 2003 Elsevier Science Ltd. All rights reserved.