Naphtha is the main petroleum derivative used as a feedstock for the steam cracking of olefins and aromatic petrochemical products. The environmental performance of the production of 1 kg of naphtha is evaluated using a Life Cycle Inventory-based emergy accounting, considering the environmental load of labor and services. The biophysical flows, which reflect the work of nature in the creation of the resources required for the production and the monetary systems, are evaluated in terms of emergy. The information recorded in a life cycle inventory (LCI) is used for the estimation of the specific emergy of naphtha. The results show that labor and services flows correspond to 10.54% and 12.93% of the total system emergy, respectively. The LCI-based emergy accounting, although being an unconventional measurement method, was found feasible bringing additional information that may help decision making.