Alternative oxidase (Aox) is encoded in the nucleus and imported into mitochondria via the general import pathway and is responsible for cyanide-insensitive respiration. It has also been shown that Aox is encoded by a small family of three to five members in several plant species divided in two subfamilies, Aox1 and Aox2. The Aox1 is present in both monocot and eudicot plant species and its induction is more obviously linked to stress while Aox2 is typically constitutive or related to development and it is only expressed in eudicots. The purpose of this work was to identify Aox genes in Annona muricata L. In order to detect different Aox genes in A. muricata we designed two degenerated primer pairs to amplify specifically Aox1 or Aox2 based in several cDNA sequences of dicotyledonous. Total RNA (1m g) isolated from leaves of 2-month-old plants and Aox1/Aox2 primer pairs were used to amplify Aox genes by RT-PCR. The RT-PCR product was cloned in plasmid vector and clones were purified and sequenced. None RT-PCR product was detected in agarose gel utilizing Aox1 primers. On the other hand, an expected cDNA fragment of 616 bp in length was obtained using Aox2 primers. The alignment of the deduced amino acid sequence with Aox proteins of others plant species revealed a higher similarity degree with Aox2 proteins of Arabdopsis (86%) and Citrus auratium (90%). When comparing the deduced amino acid sequence with both Aox2a/2b types proteins of V. unguiculata and soybean, a higher degree of similarity was observed with Aox2a than Aox2b. Our data suggest that A. muricata present at least one Aox2 gene which is expressed in leaves. Research supported by CAPES, CNPq and FUNCAP