Background: The pricing strategy of oral medications can affect their costs. The strategy of flat pricing per tablet may increase drug costs in the event of dose reductions requiring more tablets, as there is a single price for different tablet strengths, but the impact is largely unknown. With the strategy of linear pricing, the tablet price increases with its strength. We sought to determine the impact of pricing strategy on the cost of oral anti-cancer drugs during dose reductions. Methods: Oral anti-cancer drugs reviewed by the pan-Canadian Oncology Drug Review were identified between July 2011 to January 2015. The pricing strategy of these drugs was reviewed. We examined the percentage change in cost per mg and cost per 28 days as a result of dose reduction from dose level 0 to -1 and -2 for each drug. Results: Seventeen drugs for use in 20 indications were included in the analysis. There were 3 drugs for hematological malignancies and 14 drugs for solid cancers. Fifty-nine percent (10/17) of these drugs were available in multiple strengths; five of them utilized fixed pricing per tablet strategy and the other 5 utilized linear pricing. The remaining drugs (7/17) were available in a single strength tablet. Dose reductions generally increased the cost per mg for drugs using flat pricing per tablet, with a mean increase of 82% (range: 25%-200%) at dose level -1 and 100% (range: 0%-200%) at dose level -2. Dose reduction had no effect on the cost per mg of drug for drugs using linear pricing apart from lenalidomide, which had increased costs due to minimal price variation between the highest and lowest tablet strengths. In general, dose reduction did not decrease the cost per 28 days of drug for drugs using flat pricing per tablet, but was proportionally reduced in drugs using linear pricing. Conclusions: While there is a general expectation that the cost of drugs should decrease with dose reduction, oral anti-cancer drugs using flat pricing per tablet have increased cost per mg and no decrease in cost per 28 days despite dose reduction. Future economic evaluations should account for the impact of dose reductions for oral drugs using the flat pricing per tablet strategy on cost-effectiveness and budget.