We examine responses to the roll-out of antiretroviral drugs (ARVs) in Zambia in 2004, focusing on material features of the drugs (colour, shape, size, origin), 'spoiling' (concern about toxicity, side effects of the drugs) and rumours ('talk' about the drugs). Data consists of interviews with 10 people living with HIV and 21 healthcare practitioners. We found that the colour symbolism of 'traditional medicine' has some influence on ideas about ARVs, suggesting possible 'meaning responses' that could affect treatment outcomes. Respondents also become concerned when colours, shapes and side effects differ from expectations. 'Talk' about ARVs concerns risks of medication, sustainability of treatment programmes and people's feelings of vulnerability within larger socio-economic contexts in which countries like Zambia are disadvantaged. Understanding the associations that pharmaceuticals evoke can improve treatment programmes by elucidating public and patient concerns and sensitising healthcare professionals to the historical and political circumstances that condition the 'meaning' of ARVs.