Preliminary results are presented of a lichen exploration in Amapá State in Brazil. The following new species are described: Absconditella termitariicola with apothecia immersed to emergent, often partly covered by the thallus, 0.15–0.25 mm diam., pale ochraceous; asci pyriform; ascospores 1-septate, 10–12 × 4.0–5.0 μm, Astrothelium lineatum with orange thallus with orange, often linear pseudostromata with immersed ascomata in groups of 3–15; ascospores 8/ascus, hyaline, regularly muriform, 45–55 × 11–13 μm, without distinctly thickened median septum, Astrothelium unisporum with thickly corticate thallus, high, thallus-covered pseudostroma warts with 1–4 ascomata; ascospores 1/ascus, muriform, 125–148 × 35–42 μm, Coenogonium minidenticulatum with apothecia 0.2–0.4 mm diam., usually distinctly denticulate; ascospores 6–7 × 1.0–1.5 μm, with rounded ends, Crypthonia corticorygmoides with olive green felty thallus, up to 1 cm large white stromatoid-like ascigerous areas and 3–5-septate clavate ascospores of 25–29 × 5–6 μm, Cryptothecia rhizophora with white thallus with long, branching, superficial rhizomorphs of up to 0.2 mm wide, which reach until in the prothallus and ascigerous areas with lichexanthone; ascospores 85–95 × 32–37 μm, Endocarpon riparium with thallus consisting of dense agglutinated flat squamules which are not overlapping, with margins and cracks with numerous 0.1–0.2 mm diam. dorsiventral lobules of thallus-structure that are easily detached and serve as asexual propagules, Psammina tropica with sporodochia abundant in the central part of the thallus, absent in a marginal zone of 1–2 mm wide, whitish grey, irregular to rounded, ca. 0.1–0.3 mm diam., only ca. 15 μm high; conidia hyaline, palmate, with 3–6 arms, each of which are 4–7-celled, ca. 20–25 μm diam., consisting of cells of ca. 2.5–3.0 μm, Thelenella monospora with shiny grey thallus, low conical thallus-covered ascomata and ascospores 1/ascus, hyaline, ellipsoid, irregularly muriform, 75–90 × 25–28 μm, and Thelocarpon triseptatum with minute pallid perithecioid ascomata with flat tops, hamathecium thin anastomosing paraphysoids; ascospores 8/ascus, 3-septate, 12–16 × 3.5–4.5 μm. A further 209 species are reported new to Amapá State, eight are new to the Neotropics, one is new to South America and a further seven are new to Brazil. In Amapá, just as in Rondônia, Astrothelium is the most speciose lichen genus, and this may be the case all over the Amazon.