Milk remains one of the most frequently recommended solutions for storage of avulsed teeth because it can maintain cell viability and is easily accessible. However, some negative effects of milk on avulsed teeth have been reported, just as the effects of milk on the long‐term functions of cells are not clear. This study aimed to evaluate the effects of different types of milk on the viability, proliferation, and functions of periodontal ligament fibroblasts (PDLF)s in vitro. Human PDLFs were culture‐medium depleted for 5 min and stored in Hanks’ balanced salt solution (HBSS), whole cow's milk, low‐fat cow's milk, or almond milk for 1 h at 25°C. Cell viability and proliferation were assessed using MTT assays. Expression of the genes encoding type I collagen and its modifying enzymes were analyzed using real‐time PCR. Collagen matrix production was evaluated using Picrosirius red polarization. Our results showed the overall efficiency of low‐fat cow's milk in maintaining the viability and proliferation of PDLFs, and in enhancing the process of collagen production. Almond milk storage resulted in the highest rate of PDLF proliferation, and comparable collagen biosynthesis ability to the control. Therefore, besides low‐fat cow's milk, almond milk may potentially be an alternative tooth‐storage medium for PDLF preservation and PDL tissue regeneration.