In this article we show that different concepts of accounting for stock options under US-GAAP, IAS, German and Swiss accounting rules exist. Only the GASB concept requires the recognition of a personal expense at fair value. The different accounting methods can lead alone or in combination with EPS calculation requirements to huge problems concerning financial analysis. EPS calculation rules must be qualified with a special focus on the integration of stock options as not sufficient. EPS comparisons without adjustments concerning stock options should be used carefully. The paper shows further that as well the implementation of stock option plans causes implications for auditing.