This paper highlights the challenges faced by female sex workers living and working in the urban informal settlements in Nairobi, Kenya, during the Covid-19 outbreak and the aftermath of the pandemic. Using data collected through phone interviews during the immediate crisis, we document the experiences of urban poor sex workers, illustrating the acute problems they faced, including precarious housing with the reality of eviction and demolition. The paper highlights the ramifications of the Covid-19 crisis for the sex industry and predominantly women working within this informal, illegal economy. Through our empirical data we illustrate how the nature of selling sex has changed for sex workers in this context, increasing risks of violence including police abuses. We argue that examining the Covid-19 crisis through the lens of one the most marginalised populations graphically highlights how the pandemic has and will continue to deepen pre-existing structural urban inequalities and worsen public health outcomes among the urban poor. Sex worker communities are often located at the intersections of structural inequalities of gender, class, race and nation and the socio-spatial fragmentations of how they live make them some of the most vulnerable in society. We close with comments in relation to sexual citizenship, exclusionary state practices and the feminisation of urban poverty.