We describe self-reported sources of income and expenditure, and the association between part-time employment and spending on fast food, alcohol, cigarettes, and gambling for a sample of 3434 New Zealand (NZ) secondary school students (mean age 15.0 years). Disposable income was usually received from parents and guardians, but nearly 40% of students also reported receiving money from part-time employment. The proportion of students employed increased as socioeconomic rating increased, and was associated with increased purchasing of fast food and alcohol, and increased spending on cigarettes and gambling. Spending by youth has obvious public health implications, particularly when it is concentrated on products that have a negative health impact.