The construction industry in Nigeria is largely driven by activities of skilled labour or craftsmen as most of the construction activities are carried out manually. However, the Nigerian building construction firms are challenged by shortage of skilled manpower. This study assessed multi-skilling practice in building construction with a view to bridge skills shortage in the building construction firms. This study identified specific skills shortage and responsible factors, assessed the practice of multi-skilling, identified the impact of multi-skilling, identified impediments and ways of enhancing multi-skilling in the building construction firms. The study utilized a population of 170 building construction firms registered in Abuja with updated remittance to the Industrial Training Fund (ITF). Simple random sampling was used in selecting 140 sampled firms. Two sets of questionnaires were administered to the most senior professional and craftsman in each of the 140 firms sampled. Data obtained was analysed with statistical tools: Means, Percentages, and standard deviation and results were presented in charts and tables. The major findings in this study revealed that respondents (professionals and craftsmen) admitted shortage of Masonry, Plumbing, and Painting skills. “Poor Apprenticeship Schemes” was unanimously agreed by respondents to be the most important factor responsible for skills shortage with mean of 3.94 and 3.74 as ranked by professionals and craftsmen respectively. The study also revealed that multi-skilling is only slightly (48%) practiced among professionals while some of the craftsmen possess and practice skills other than their traditional area of competence. The study showed that professionals and craftsmen admitted that “Work Force Saving” (Mean = 3.83 and Mean = 4.13 respectively) is the most important impact of multi-skilling. Findings on impediments to multi-skilling revealed that “high cost of training” (Mean = 3.78) and “complexity of management” (Mean = 3.51) are the major impediments. “Training and Retraining of workers” (Mean = 4.14) and „management‟s decision to multi-skill” (Mean = 3.90) were ranked highest as ways of enhancing the practice of multi-skilling. The research therefore concludes that “Workforce Saving” attribute of the concept of multi-skilling is an antidote to skills shortage in the building construction industry in Nigeria. Therefore, study recommends that construction firms should adopt multi-skilling with sustainable implementation strategies in order to bridge skills shortage.