Fungal pathogens are the main cause of losses in terms of fruit and vegetable yield in the field and product after harvest. Given the low number of treatments allowed after harvest, for overcoming losses there is a growing interest towards the use of eco-friendly means as biocontrol agents and/or food additives, also known as Generally Recognised as Safe (GRAS) compounds, which are low-toxicity substances having minimal toxicological effects on animals and negligible environmental impact. This study assessed the presence of Alternaria rots on tomato fruit commercialized in Egypt, highlighting the occurrence of Alternaria arborescence but mainly Alternaria alternata strains. Furthermore, this investigation presented the result of in vitro and in vivo laboratory assays using new antagonistic bacterial strains and GRAS compounds against for postharvest tomato fruit rots by Alternaria spp. Two Pseudomonas ssp. strains were selected and combined with the GRAS substances that showed antifungal activity to evaluate the putative improved effect. Results proved that the two Pseudomonas spp. strains almost completely prevented the disease onset independently if used singly or in combination with GRAS. These results although preliminary seem promising and need to be confirmed in large-scale trials.