The objective of this study was to evaluate in ‘Smoothee Golden Delicious’ apples, the use of backscattering images as a non-destructive method to estimate some quality parameters during the ripening process of fruits. In this experiment, 208 apples were collected from an experimental orchard of the Estación Experimental de Aula Dei (CSIC) in Zaragoza (Northeastern, Spain). Backscattering images were kept from samples picked up every 15 days during 7 months until harvest. In the same fruits, soluble solids contents (SSC) and firmness were measured by traditional destructive methods. The light source was a solid state laser diode module emitting at three different spectral bands (670, 785 and 980 nm) PLS calibration methods were used to create the statistical model to predict SSC and firmness. Good results were obtained when PLS calibration was applied to Feret diameter corresponding at different levels of gray. The Rcv2 values were 0.87 for firmness and 0.93 for SSC, which are higher than other reported in the literature for the same commodity.