A stress-mediated electrocaloric (EC) effect in Bi4Ti3O12 ferroelectric nanoparticle was predicted using a phase field simulation in combination with a thermodynamics analysis. The Bi4Ti3O12 nanoparticle exhibited both a positive and negative EC effect under the applied electric fields. The negative EC effect was transformed into the positive EC effect under compressive stress; however, the negative EC effect appeared across a wider temperature range than the positive effect and could even be enhanced under tensile stress. The results provide a new way to tune the sign of the EC effect and to enhance the EC coefficient in ferroelectric materials. (C) 2017 Elsevier B.V. All rights reserved.