Employment conditions are important social and commercial determinants of health. Informal employment—also known as ‘cash-in-hand’ and ‘undeclared’ work—is a discrete employment condition that has salience around the world. Fuelled by neoliberal ideology, informal employment has become increasingly common in high-income countries. Public health research concerning the health of informal workers comes largely from low- and middle-income countries, where the phenomenon is more visible. There has been little research on the health effects of informal employment in high-income countries including Australia. Twenty-nine workers aged 18 years and older, who were undertaking informal work activities, were recruited using social media and an online marketplace in Tarndanya (Adelaide-Kaurna Country), Australia. Qualitative narrative data, demographic profiles, and physical and mental health scores were collected. Most informal workers reported unfair and indecent employment conditions including job insecurity, low income, coercion, and lack of respect and dignity at work, and were often exposed to unsafe and unhealthy work environments. Workplace injuries and exposure to occupational hazards were common; and Physical and Mental Component Scores were poorer among informal workers when compared to the population of South Australia as a whole. With informal employment in Australia described as part of a ‘significant, pervasive, damaging and growing’ problem, there is a need for a health promotion lens over industrial relations policies in the interest of creating equitable access to fair and decent work.