The present study examined the effect of ACT-2, a K-vitamin group activator intensively applied to tomato (Lycopersicon esculentum Mill.), on the anatomy, morphology, and viability of tomato pollen from plants grown under greenhouse conditions. The activator was applied to tomatoes at the recommended dosage (150 cc/100 L of tap water) and double the recommended dosage (300 cc/100 L of tap water). Pollen width and length, exine and intine layer thickness, pore width and length, and crevice width and length were measured using an ocular micrometer. Reductions were observed in all the measured parameters in all application groups, except for pollen width and length values at the 150 cc/100 L dosage, as compared to the control group. The viability of the pollen, as determined by triphenyl tetrazolium chloride, decreased in all the application groups as the dosage increased, as compared to the control group, and the toxic effect became more evident at the 300 cc/100 L dosage. In particular, non-viable pollen types, such as wrinkled pollen and abnormally shaped pollen, were observed in the fungicide groups. Additionally, the activator caused changes in the morphological structure of the tomato pollen. The morphological structures of some pollen, such as subprolate and suboblate, which were not observed in the control group, were seen in pollen in the polar view at the 150 cc/100 L ACT- 2 dosage.