South Africa is facing an established epidemic of methamphetamine, known locally as “tik”. Globally, methamphetamine has been linked to high rates of sexual risk behaviors, including sex trading. The goal of this study was to qualitatively examine the experiences of sex trading among methamphetamine users in Cape Town, South Africa. Individual in-depth interviews were conducted with 30 active methamphetamine users (17 men and 13 women) recruited from the community. Interviews were conducted in local languages using a semi-structured guide that included questions on sex trading experiences and perceptions of sex trading among methamphetamine users. Interviews were audio-recorded, transcribed, and analyzed using analytic memos and coding with constant comparison techniques. The data revealed that in a setting of high levels of addiction and poverty, sex was an important commodity for acquiring methamphetamine. Women were more likely to use sex to acquire methamphetamine, but men reported opportunistic cases of trading sex for methamphetamine. Four models of sex trading emerged: negotiated exchange, implicit exchange, relationships based on resources, and facilitating sex exchange for others. The expectation of sex trading created a context in which sexual violence against female methamphetamine users was common. Multiple sexual partners and inconsistent condom use in acts of sex trading put methamphetamine users at high risk of HIV. Interventions in this setting should address addiction, which is the primary driver of sex trading among methamphetamine users. Harm reduction interventions may include education about HIV and other sexually transmitted infections, availability of condoms and HIV testing, and sexual violence prevention.