Aflatoxin B1 (AFB1) was detected in 57% of the nuts and nut products marketed in Penang, Malaysia using the liquid chromatography tandem mass spectrometry. The contamination levels ranged from 0.40 to 222 μg/kg and 17 out of 128 samples (13.3%) contained AFB1 above the European Commission permitted level (2 μg/kg). Estimated dietary exposure of AFB1 in nuts and nut products were 0.36 ng per kg body weight and day and 8.89 ng per kg body weight and day, representing the low and high-level of exposure, respectively. Dose-response modelling resulted in benchmark dose lower confidence limit (BMDL10) values of 0.305 ng per kg body weight and day, with the best fitted from the log-logistic model. The derived margin of exposure (MoE) values ranged from 34 to 847 suggested that AFB1 would be of public health concern and might reasonably be considered as a high priority for risk management actions.