We present a statistical analysis of 248 luminous infrared galaxies (LIRGs) which comprise the Great Observatories All‐sky LIRG Survey (GOALS) observed with the Infrared Spectrograph (IRS) on‐board Spitzer in the rest‐frame wavelength range between 5 and 38 μm. The GOALS sample enables a direct measurement of the relative contributions of star‐formation and active galactic nuclei (AGN) to the total infrared (IR) emission from a large, statistically complete sample of LIRGs in the local Universe.Several diagnostics effective at isolating the AGN contribution to the Mid‐infrared (MIR) emission using [NeV], [OIV] and [NeII] gas emission lines, the 6.2 μm PAH equivalent width (EQW) and the shape of the MIR continuum are compared. The [NeV] line which indicates the presence of an AGN is detected in 22% of all LIRGs. The 6.2 μm PAH EQW, [NeV]/LIR, [NeV]/[NeII] and [OIV]/[NeII] ratios, and the ratios of 6.2 μm PAH flux to the integrated continuum flux between 5.3 and 5.8 μm suggest values of around 10% for the f...