Background: Vital pulp therapy procedures in primary dentition focuses on preservation and maintenance of pulp tissue that has been compromised due to caries, trauma, etc. Several pulp dressing materials have been used in primary teeth and some natural materials from the field of traditional medicine have also been introduced as medicaments in vital pulp therapy. The understanding of biologic and cytotoxic properties of newer materials is important for safe clinical usage. The biologic compatibility of these newer materials is imperative to limit or avoid tissue irritation or degeneration. Aim: To evaluate the cytotoxic effects of Allium sativum on cultured human primary dental pulp fibroblasts. Materials and methods: Primary pulp fibroblasts were cultured from the pulp tissue obtained from extracted deciduous primary canines and central incisor teeth. The freshly prepared concentrations of 1000, 500, 250, 125, and 62.5 µg/mL A. sativum extract were added to the 96-well plate in triplicates to which culture medium containing fourth passage cell suspension was added previously. Cells without treatment served as control, while cells treated with 5% dimethyl sulfoxide (DMSO) served as toxic control. After the addition of experimental and control agents, cells were incubated for 24 and 48 hours at 37°C in 5% CO₂ atmosphere. After the incubation period, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the number of viable cells. Absorbance was read with a microplate reader at 570 nm wavelength and the relative viability of dental pulp fibroblasts at various concentrations was expressed as color intensity of the experimental wells relative to that of control. The percentage of cell viability was also calculated accordingly. Results: The MTT assay results revealed that A. sativum extract, in all the concentrations tested at both the time intervals maintained a cell viability of greater than 90%. At 24 hours, the mean absorbance value of untreated control wells was recorded as 0.84400 ± 0.00916 with 100% cell viability. Among all the concentrations of garlic extract tested, highest mean absorbance value of 0.83933 ± 0.00550 with 99.44% cell viability was recorded for 62.5 µg/mL concentration. At 48 hours, the mean absorbance value of untreated control wells was recorded as 1.22767 ± 0.01106 with 100% cell viability, and the highest mean absorbance value of 1.22567 ± 0.01006 with 99.83% cell viability was recorded for 62.5 µg/mL concentration. The cell viability did not seem to be affected by the concentration of A. sativum extract at 24 hours. However, at 48 hours, the sensitivity of the cells was observed to be dependent on the concentration of A. sativum with a decrease in the viability of cells noted with the increase in concentration. Conclusion: A. sativum extract is noncytotoxic in nature and preserves the vitality of cultured human primary dental pulp fibroblasts making it a suitable material for use in vital pulp therapy procedures of primary teeth.