By car, take the Great Western Highway from Sydney to Dubbo, and then the Mitchell Highway to the Barrier Highway, which will take you to Broken Hill. Southern Australian Airlines (book through Qantas, tel. 13 13 13 in Australia) also connects Broken Hill to Adelaide, Melbourne, and Mildura.
Greyhound Australia (tel. 13 14 99 in Australia, or 07/4690 9950; www.greyhound.com.au) runs buses from Adelaide for around A$60; the trip takes 7 hours. The 16-hour trip from Sydney costs from A$96.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.