An increasing number of infants are being made sick by dairy products contaminated with melamine. As a result, many countries have adopted additional requirements for milk-based food products. The scope of the present study was to assess amounts of melamine in some dairy products from Zanjan market, Iran. Amounts of melamine in samples of milk, yoghurt, infant formula, coffee mate and cheese were determined in five different brands by the high-performance liquid chromatography with ultraviolet detector system. In total, 225 samples were determined (five products × five brands × three samples × three repeated measurements). Amounts of melamine in samples (in μg/g) were determined in the range of 0.20–0.26 for milk, 0.57–0.99 for yoghurt, 0.35–3.40 for infant formula, 0.09–1.23 for coffee mate and 0.30–2.50 for cheese, and the mean values of melamine in products were evaluated as 0.24, 0.76, 1.38, 0.56 and 1.16, respectively. The minimum and maximum values for amounts of melamine were recorded in milk and infant formula, respectively. Comparison of test results with the standards set by the European Union and the US Food and Drug Administration for maximum residue-level values for dairy products contaminated with melamine showed that levels determined by tests had higher health risks than the regulations allowed. Iran has not yet adopted regulations to control levels of melamine in food products. The results show that maximum residue-level values need to be determined for melamine in Iranian dairy products, and foods should be monitored daily for levels of melamine contamination.