Personal digital assistants (PDAs) are part of the new technologies applied to medicine, which could improve both access to and storage of distinct databases. The present article reviews some general technical features, as well as the utility of these devices for consulting specific pediatric, clinical and pharmacological databases. A search was performed in Medline (1999 to 2004) and of web pages that described the use of PDAs and a total of 46 useful applications were identified, including pediatric diagnostic and treatment guidelines, databases of diagnostic procedures, guidelines for antibiotic therapy in the pediatric and adult populations, databases to establish the diagnosis and treatment of patients in emergency and intensive care medicine, catalogues of general drugs with complete pharmacological data (indications, doses, adverse effects, interactions, toxicology, pregnancy, lactation), specific databases of neonatology, otorhinolaryngology and pediatric surgery, and medical calculator software. Each reference details the contents, source of the reference information, memory requirements, operating system, cost, web page for downloads and whether there is a test version. There is a wide variety of pediatrics software for PDAs. Once the quality of these databases has been assessed, each user should evaluate which application will be most useful depending on his or her needs.