Standardization of second opinion question-answer pairs with a classification system can be used to facilitate data sharing and reuse. The Brazilian telehealth program faces the problem of representing biomedical knowledge from the primary care second opinion demands generated by rural health care teams. The objective is to determine if one of the medical classification systems has a superior ability to standardize Portuguese-language second opinion question-answer pairs. Data from 2,638 second opinions from 2010 were randomly reduced to a 264 question-answer pair data set. The semantic meaning of the question-answer pairs was manually assigned to an International Classification of Primary Care, Second edition (ICPC2) code. Eight question-answer pairs did not contain sufficient medical semantic meaning to allow for mapping to an ICPC2 code; 53 question-answer pairs did contain sufficient medical semantic meaning for mapping, however an appropriate ICPC2 code did not exist; and 203 question-answer pairs did contain sufficient medical semantic meaning for mapping to an ICPC2 code. A review of the literature indicates that there is no baseline to compare the 77% success rate against.