The Amazon River is known as a region of intense biochemical reactivity. As a result of increased anthropogenic impacts in its catchment (e.g. population growth, agriculture, and deforestation), the Amazon River is undergoing fundamental changes. During the RV METEOR cruise M174 (doi:10.1594/PANGAEA.935041), six stations were visited to study the nitrogen cycling and productivity of the Amazon and Pará estuaries, which is crucial to estimate the ecosystem's health. This dataset presents rates of various nitrogen cycle processes (nitrification, nitrate, ammonium, and amino acid uptake rates) as well as associated dissolved inorganic carbon uptake rates. Rates are presented as volumetric rates, as well as rates integrated over the euphotic zone (3 to 10 meters).