This study measures the effect of productive failure instruction in a digital inquiry environment on developing deep understanding and achievement of organic chemistry among Saudi Arabian secondary school students. The study adopted the experimental design of control and experimental groups with pre- and post-measurements. The sample comprised 66 secondary school students from Wadi Al-Dawasir Governorate, Riyadh, Saudi Arabia, distributed into the experimental group (n = 32) and the control group (n = 34). The data collection utilised the deep understanding test and the achievement test of organic chemistry. The results revealed that there were statistically significant differences at [alpha] = 0.05 between the means of the scores of the experimental and control groups in the deep understanding level and the achievement test of organic chemistry in favour of the experimental group. Recommendations and suggestions are also presented in light of the study results.