As a result of the continuous development of the business environment, many traditional organizations decide to implement electronic commerce (ecommerce). Implementing ecommerce successfully may generate highly rewarding results, while an inefficient implementation may lead to endan- germent of the organization's survival. The critical question is therefore what factors that are critical for an ecommerce strategy implementation to succeed.

The purpose of this is to investigate what factors that are critical to achieve a successful implementation of an ecommerce strategy in retail businesses. According to this purpose, three research questions have been formulated to arrive at valuable findings within this field.

In order to fulfill the purpose of this thesis a qualitative research method with an exploratory approach is being applied, data are collected through case study interviews. The cases are being arrived at by nonprobability sam- pling in form purposive sampling.

When comparing critical success factors identified in theory and practice, the result suggests that integrated management teams, culture management, realistic expectation and compensation systems are not critical for success- ful ecommerce implementation. Factors that are critical for success are fi- nancial and time investments, sufficient knowledge and technological skills, committed leadership, communication, SEO, omni-channel, external part- ners and the pre phase.