This article presents recommendations for the design of conceptual models for applications via handheld devices such as personal digital assistants and some mobile phones. The recommendations were developed over a number of years through experience that involves design of conceptual models, and applications of these multimedia representations with students in schools and higher education. Three sets of design recommendations are discussed: design presentation of conceptual models, small screen design, and design in relation to specific learning uses. These recommendations should prove useful to designers of multimedia resources and professionals engaged in instructional uses of these representations. The article calls for researchers to pay more attention to the design of conceptual models and other forms of multimedia resources and their instructional uses. (Contains 2 tables and 3 figures.)