Three years of weekly Rotorod airborne allergen reports from Corpus Christi, Texas, were reviewed. Five of 10 newly available airborne molds for radioallergosorbent testing (RAST) were present in significant numbers. Three hundred seventy-five mold RAST evaluations were expanded to include the five old and these five new molds. Except for Alternaria, the frequency of and allegenic response to the new molds were generally greater than those for the five old molds. The usual Alternaria-Cladosporium mold screen proved less satisfactory when these five new molds were added to the mold battery; however, the addition of Helminthosporium to the screen corrected this deficiency. Cross-reactivity production of false-positive responses seems unlikely because of frequent significant variance in RAST scores from mold to mold in the same patient.