This research investigates the interrelationships of modality strength, modality preference, field dependence-independance, sex, ecological group, and their contribution to mathematics achievement among 256 fourth-grade Puerto Rican students from four ecological environments. Ecological factors were defined as characteristics that make city areas distinct from one another in terms of, among others, physical surroundings, sound and visual stimuli, interactions, and kinds of activities. Data from four instruments were obtained and analyzed. Results suggest that ecological factors influence learning style and mathematics achievement. Auditory learners tend to live in the rural environment, mixed in the urban, and haptics in the suburbs. Rural children tend to be field-independent. In females, field dependence-independence is significantly explained by the joint contribution of modality strength and ecological group. A large proportion of mathematics achievement variance can be attributed to the joint contribution of ecological group and field dependence-independence in both males and females. In females, the greatest independent contributor seems to be field dependence-independence, while in males, it is ecological group. Since previous research had not considered ecological characteristics, these findings open new avenues of exploration in our quest for knowledge on learning style components. (Author)