The influence of tea tree essential oil (TTEO) and modified-atmosphere packaging (MAP) on the quality of grated anco squash (AS) (Cucurbita moschata) was studied. AS (obtained in Santiago del Estero-Argentina) were washed, sanitized, cut, peeled, grated, washed, and centrifuged. The product was then subjected to TTEO treatments at two concentrations (4 and 8 μL/mL) and applied in three ways: spraying (TA), immersion (TI), and strips soaked in EO adhered to the storage container (TV). A NaClO immersion treatment (TH) and a control (immersion in water) (TC) were also included. All samples were conditioned in trays coated with 35 mm polypropylene to generate MAP and stored for 8 days at 5 ºC. Samples from each treatment were analyzed in triplicate at 24 h and 8 days, assessing sensory quality, antioxidant, and microbial growth (mesophiles, psychrophiles, and enterobacteria). The sensory evaluation was carried out by 11 trained individuals, who assessed six attributes on a scale of 1 to 9, with aroma and flavor being critical parameters from the judges' acceptability point of view. The results showed that applying TTEO at a higher concentration (8 μL/mL) in all forms was an appropriate strategy for maintaining microbiological quality for 8 days, although this concentration significantly affected aroma, decreasing its acceptability. TA had the highest values ​​(P <0.05) and was the most accepted until the fourth day. No changes were observed in phenolic compounds and an increase in antioxidant capacity and carotenoids was recorded at the end of storage. According to the parameters studied, the use of TTEO (8 μL/mL) with MAP was effective in maintaining the overall quality of AS for 4 days. For this reason, the use of TTEO could be considered to improve the nutraceutical profile of AS and also in conjunction with other technologies to prolong its shelf life.