Aceria guerreronis Keifer and Steneotarsonemus furcatus De Leon are phytophagous mites that attack coconut fruits. These mites establish their colonies under the bracts in the perianth where they feed, causing necrosis and a loss of fruit quality and commercial value. Phytoseiidae is considered the most important family for the control of pest mites. With 256 species documented, the Phytoseiid fauna in Brazil is highly diversified. They are distributed across all Brazilian biomes, including the Amazon, Caatinga, Cerrado, Pampa, Atlantic Forest, and Pantanal. Regardless of the fact that the Amazon biome occupies an estimated 49% of the Brazilian territory, its acarofauna remains unexplored. In this region, coconut is one of the most cultivated crops, although the variety of mites in this crop in the Amazon is yet unclear. This information is essential since there are potential predatory species that can play an important role in the biological control of coconut pests. Thus, the present study investigated the diversity and seasonality of mites in coconut fruits in the Eastern Amazon production region throughout the year. Data were collected monthly and analyzed to determine the diversity and seasonality. The faunistic indices were calculated using the program ANAFAU, and the abundance and diversity of phytoseiids were analyzed using the software EstimateS. As the fruit ages, the quantity of injured fruits increases. The mites collected belonged to the families: Oribatida (20), Rhodacaroidea (14), Eriophyidae (473,904), Phytoseiidae (147), Tarsonemidae (133), Ascidae (122), Bdellidae (110), Tydeidae (59), Cunaxidae (7), Eupodidae (7), Cheyletidae (5), Blattisociidae (4), and Cryptognathidae (1). Throughout the collection period, A. guerreronis and S. furcatus were detected on fruits with and without damage, with A. guerreronis being the most prevalent. Predatory mites of the Phytoseiidae family were sampled from 12 collections, totaling 147 specimens distributed across eight species. Amblyseius aerialis (Muma) was the predominant predator species. The peak population of A. guerreronis and S. furcatus occurred in different periods, although both species were sampled during periods of high precipitation, suggesting adaptation to the climatic conditions of the region. Temperature was strongly correlated with mites of the Phytoseiidae family. The occurrence of these mites was more common in months with higher temperatures. The mite A. aerialis was discovered in 12 evaluations, with a greater occurrence in October 2019 and August 2020. Understanding the diversity, abundance, and population fluctuations of pest mites and their natural enemies in coconut plants is critical for developing integrated pest management strategies.