Aim:The aim of this study is to evaluate the effect of temperature change on film thickness of both types of cements. Materials and methods:Totally, 60 samples were prepared with 10 in each subgroup, thus comprising 30 in each group. Materials tested were glass ionomer cement (GIC) type I and zinc phosphate type I. Samples were manipulated with manufacturer's instructions and tested according to American Dental Association (ADA) guidelines. Results:The mean values of film thickness were recorded for both groups I and II. In intragroup comparison of group 1, subgroup III (26.560 ± 0.489 µm) was found to have the highest film thickness followed by subgroup II (24.182 ± 0.576 µm) and the lowest in subgroup I (20.209 ± 0.493 µm). In intragroup comparison of group II, the film thickness recorded in subgroup III (25.215 ± 0.661 µm) was the highest followed by subgroup II (21.471 ± 0.771 µm) and the least in subgroup I (17.951 ± 0.654 µm; p < 0.01). In intergroup comparison of groups I and II, group II (21.545 ± 0.841) was found to have less film thickness than group I (23.650 ± 0.271). The results were found to be statistically significant (p < 0.01). Conclusion:Both zinc phosphate and GICs can be used satisfactorily for luting purpose. The temperature fluctuations have a direct influence on the film thickness. Zinc phosphate has less film thickness than GIC.Clinical significance: Zinc phosphate should be preferred over GIC in clinical practice, and more stress should be given in mechanical preparation of crowns for better retentive quality of prosthesis.