The giant African snail is currently one of the most aggressive and invasive species that has colonized many countries outside its nat- ural environment. We recorded four shell measures and the weight of 3 157 individuals of Achatina fulica collected in Boyaca, Cundinamarca, Meta, Norte de Santander and Valle del Cauca, Colombia. Larger and heavier individuals were collected in the Meta and Boyaca depart- ments while the highest density per square meter was recorded in Cundinamarca. We found a strong, positive and highly significant (p<0.01) correlation among measured variables. During development maximum sizes of shell, opening and body weight are correlated, and shell length increases faster than the other measures, leading to a marked elongation of the individuals. The settling time of the popula- tions was also reflected in the size of individuals.