Learning and development is needed to retain a flexible and competent workforce. It prevents employees’ skill shortages and increases commitment to their organization. Various studies show empirical evidence on the positive relationship between Human Resource Development (HRD) initiatives and employee commitment and reduced intention to leave. Older workers face employability problems as compared to their younger colleagues. These problems usually increase as the years mount resulting in a growing number of workers taking early retirement or spending several years of incapacity before retiring. Older workers’ lower participation in HRD initiatives is perceived as one of the reasons for these problems. However, the usual stereotype of ageing workers not engaged in any learning activity does probably not apply if one takes informal learning into account. Further more, all learning situations hold attributes of formality and informality which can be grouped into four aspects of learning, i.e.: location/setting, process, purposes, and content. ‘HRD intervention’s level of formality’ implies each HRD initiative as in/formal to a more or lesser degree. In this contribution we focus on the impact of HRD-intervention’s level of formality on organizational commitment. We particularly focus on differences between and within employees of various age groups in large as well as medium sized Dutch companies from different sectors of industry. The presented study builds on a single SME case study which was done in 2008. Results will positively affect age-related HRD policy and practices in work organizations.