AIMS: To describe the work, family socioeconomic characteristics, and growth of a representative sample of working children in Jordan. METHODS: In a cross sectional survey of growth and health, 135 working children (aged 10-16 years) were studied in the areas of Irbid, Jarash, and North Jordan Valley. The children and their parents were interviewed and data collected on length of working week, income earned by the child, duration of work in years, age of starting work, type of work, child's smoking status, and family socioeconomic status. RESULTS: The mean age of the children was 13.3 years; 14.8% had started work before the age of 10 and 12.6% had been working for more than four years. Mean income was 34 Jordanian Dinars but 6.7% were unwaged; 34% were working more than 60 hours per week, and 85.9% more than 40 hours. Monthly income and working hours were positively correlated with the age of the child. There was no correlation between age and smoking status; 37.8% smoked more than five cigarettes per day. Mean height and weight z scores were -0.365 and -0.081 of the UK standard respectively. Packed cell volume was within the anaemic range in 34.1% of children. CONCLUSIONS: In Jordan many children start work at an early age and work long hours for little or no income. Stunting and anaemia are common and many are established smokers. Relevance of these findings for social policy and health care of working children in Jordan and elsewhere is discussed.