Two areas in the Atlantic Forest (São Paulo State, Brazil), with contrasting environments in respect of human occupation, were monitored from 1999 to 2001. One area named PEFI (23°38'08''-23°40'18'' S and 46°36'48''-46°38'00'' W) at an altitude of 798 m a.s.l., 526.4 ha in area and about 50 km from the sea, lies in a State Park within the largest metropolis of South America - São Paulo. The other area, named CUNHA (between 23°13'18'' and 23°16'10'' S and 45°02'53'' and 45°05'15'' W) about 1050 m a.s.l. with an area of 2854 ha and about 15 km from the sea, is also within a State Park in the Atlantic Forest, but is surrounded by rural areas and small villages. For each area, the rainfall and throughfall chemistry were examined and pH and Na⁺, K⁺, Mg²⁺, Ca²⁺, NH₄⁺, Cl^-, NO₃^- and SO₄^2- as well as trace metals were determined. Compared with PEFI, CUNHA is characterised by low chemical fluxes and the largest differences are for the ions such as Ca²⁺, H⁺, NO^3- and SO₄^2- which are mainly anthropogenic in origin. Differences in throughfall chemical fluxes are linked to the nutritional status of the trees.