Abstract Cost-benefit decision-making is a procedure by which an organism chooses among different choices when each choice indicates an operation linked to a different outcome. In addition, there is considerable evidence showing that opiates affect several aspects of cognition, including cost-benefit decisions. In the present study, we evaluated functional and neural synchronization between the orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC) while value-based decision-making in pre-morphine dependency and morphine dependency times in rats. A T-maze decision making task with a differential expense (high vs. low endeavor) and remuneration (high vs. low remuneration) was performed and local field potentials (LFP) from the OFC and ACC were recorded simultaneously. Results demonstrated that neural simultaneity was seen in theta and low beta frequencies between both regions, when the animals chose high endeavor/high remuneration. However, while the rats preferred low endeavor/low remuneration in pre-morphine dependency time and morphine dependency time, neural synchronization was insignificant. The obtained findings clarified that functional connection and neural simultaneity between the ACC and OFC in theta and low beta frequencies has an essential role in endeavor-based decision-making, and disturbance of make a decision in morphine-treated animals is associated with changes in this frequency range in the OFC and ACC.