This study aims at investigating a possible pathway of cytotoxicological status of the diterpenoid essential oil, phytol (PYL). For this brine shrimp lethality bioassay (BSLB) and hemolysis (HL) test systems were selected. In the BSLB, PYL either alone or co-treated with ethylenediaminetetraacetic acid (EDTA), potassium di-chromate (K 2 Cr 2 O 7 ; KD), copper sulphate (CuSO 4 .5H 2 O; CS) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox, TRO) as membrane lyser, strong oxidizer, oxidizer-cytogenotoxicant and antioxidative-cell-protestant, respectively. The HL was carried out in rat erythrocytes (RBCs) taking TRO as a standard. In addition, to view a time-dependent cytotoxic activity of PYL, the mortality of the shrimps was counted at 24 and 48 h. Results suggest PYL is non-cytotoxic at low (40-160 µM) but toxic at high concentration (2-8 mM) to the shrimps and RBCs. An increased cytotoxicity was observed for 24 h to 48 h in brine shrimps. In both cases groups co-treated with cytotoxicants/protestant suggest that PYL is cytoprotective in the presence of oxidizer. The cytoprotectivityof PYL may be connected to its antioxidant potential and cytotoxicity for antioxidant-mediated pro-oxidative effects. In conclusion, PYL is cytoprotective at low concentration but toxic at high, activities found, however, may be linked to the radical scavenging pathway.