Microplastic (MP) pollution has been recognized as one of the greatest threats to aquatic biota, becoming one of the most studied issues in the recent environmental impacts literature. The number of publications on MPs has increased exponentially since the 1990's. In developing countries like Brazil, the study of MPs is even more recent, and most of the scientific production is concentrated in the last 10 years. This pattern fits perfectly for the Amazon: up to June 2020, only 34 publications were available for the region, 10 (29.4%) peer-reviewed articles and 24 (70.6%) grey literature documents. Most studies were conducted in Brazilian Amazon (32) and were published between 2010 and 2020, but 83.3% were from the last two and a half years (2018 to 2020). The main subjects investigated were environmental screening and monitoring of microplastics (38%), ingestion and uptake of MPs by biota (35%), physiological effects of MPs (15%) and potential biomonitor species (12%). Plastic fibers was the dominant type of MPs in 50% of the publications and the size analyzed varied from 1 µm to 5 cm. Nearly half of the publications (16) used analytical tools for identifying the plastic polymers. The most common identified polymers were Polyamide, Polyethylene (PE), Polypropylene (PP), Rayon, Polyethylene terephthalate (PET), polystyrene (PS), acrylonitrile butadiene styrene (ABS), polyurethane (PU), Poly(methyl methacrylate) (PMMA) and polyvinyl chloride (PVC). This review shows that microplastic contamination is already a reality for the Amazon environment and related biota. Negative effects at different ecological levels are probably taking place in the ecosystem. However, limited studies, lack of standardized methodologies and methodological flaws make it difficult to establish the fundamental knowledge necessary to evaluate the environmental levels and impacts of MP in the region, becoming urgent the need to improve scientific knowledge and laboratory infrastructure to study MPs in Amazon.