Abstract The oil and headspace of fresh white flesh guava fruits (Psidium guajava L.) from trees grown in Reunion island were obtained by steam hydrodistillation and headspace solid-phase microextraction (SPME), respectively. The chemical composition of the extract was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). A total of 73 compounds were identified, of which 61 by hydrodistillation and 24 by headspace SPME. In the headspace, the major constituents were: hexanal (65.9%), γ-butyrolactone (7.6%), (E)-2-hexenal (7.4%), (E,E)-2,4-hexadienal (2.2%), (Z)-3-hexenal (2.0%), (Z)-2-hexenal (1.0%), (Z)-3-hexenyl acetate (1.3%) and phenol (1.6%), while β-caryophyllene (24.1%), nerolidol (17.3%), 3-phenylpropyl acetate (5.3%) and caryophyllene oxide (5.1%) were the major volatile constituents present in the hydrodistilled oil. Many compounds were identified for the first time in the guava fruit such as γ-butyrolactone (7.6%) in the headspace SPME and nerolidol (17.6%) in the oil. In addition some compounds such as (Z)-3-hexenal, (E,E)-2,4-hexadienal, γ-butyrolactone, borneol, phenol, cuminyl alcohol could be identified only by the headspace method (SPME).