Ambient aerosol samples from central Amazonia were analyzed for the presence of (2R,3S)- and (2S,3R)- methylerythritol and (2S,3S)- and (2R,3R)- methylthreitol, four stereoisomers that may have primary and secondary origins from the biosynthesis and oxidation processes of isoprene within plants and also in the atmosphere. The 2-methyltetrols were detected in aerosol samples collected at a measurement site near Manaus, Brazil in a remote tropical rainforest environment between June 2008 and June 2009. Average concentrations of 78.2 and 72.8 ng m-3 were observed for (2R,3S)- and (2S,3R)- methylerythritol and 3.1 and 3.3 ng m-3 for (2S,3S)- and (2R,3R)- methylthreitol during the dry season. In the wet season, the average concentrations were 7.1, 6.5, 2.0, and 2.2 ng m-3, respectively. The enantiomer fractions (Ef) were on average 0.52: 0.48 for (2R,3S)- and (2S,3R)- methylerythritol and 0.46: 0.54 for (2S,3S)- and (2R,3R)- methylthreitol. The concentration of these isoprene oxidation products attributed to primary origin ranged between 0.8 and 53.8 ng m-3 for the 2-methylerythritols and between 0.3 and 2.1 ng m-3 for the 2-methylthreitols. The 2-methylerythritols show no correlation with isoprene emission estimates whereas 2-methylthreitol displays a negative correlation. The present study reinforces the importance of the analysis of chiral organic compounds to correctly assess the relative contribution of primary biogenic emissions and isoprene oxidation products to biogenic secondary organic aerosol.