The growth of poultry industry in Peru has increased the production of eggshell. This material is interesting as a chemical amendment for acidic soils. The present research was conducted under laboratory conditions with the aim of studying the feasibility of using milled eggshells as liming material and source of bioavailable calcium. An acid soil of Ucayali was amended with milled eggshell in two particle sizes: fine powder (53-106 μm) and non-sieved (< 1.7 mm). Both fractions were applied at rates equivalent to 100, 200 an 400% of exchangeable acidity including one control without amendment. The soil was incubated at room temperature during 135 days. Soil pH, exchangeable acidity and contents of exchangeable (KCl 1N) and extractable calcium (Mehlich-3) were measured at 45, 90 and 135 days of incubation. Both fractions showed very similar effect on evaluated variables. Soil pH and contents of exchangeable, and extractable calcium increased proportionally to the rate applied. The rate equivalent to 100% of exchangeable acidity allowed to reach pH values lower than 5.4 but it was enough to neutralize all the exchangeable acidity since 45 days. Extractable calcium showed a high correlation with exchangeable calcium. Milled eggshell showed a high potential as a liming material for acidic soils of the Amazonia.