Condom and contraceptive use at first intercourse have become important reference points in monitoring the sexual health of young people. This study describes the precautionary practices of a national stratified cluster sample of 3133 Australian hairdressing, automotive, and commercial cookery apprentices aged 15 to 24 years. Approximately 77% of the apprentices reported using a condom, the oral contraceptive, spermicide, IUD, or a diaphragm at first intercourse. Of these, 91.7% used a condom either alone or in combination with another method. Among female apprentices, younger age at the time of the survey, year 10 or more schooling, being older at first intercourse, being the same age or older than their partner, and planning first intercourse were associated with increased condom use. First intercourse with a regular partner and planning first intercourse were associated with greater likelihood contraceptive use. Male apprentices were more likely to use condoms, and to use contraception generally, if they were younger at the time of the survey, older at first intercourse, and were involved in planning their first occasion of intercourse. No significant differences were found in rates of precautionary use between the sexes. Rates of condom and contraceptive use at first intercourse in this Australian sample were comparable to those of other developed countries. However, there is still a worrying degree of non-use, especially among those who engage in intercourse early in their teenage years, who are forced or coerced into sex, or do not plan their first occasion of intercourse.