This study critically examined the relationship between workers welfare and organizational effectiveness of Shell Nigeria Exploration and Production Company (SNEPCO), Lagos, Nigeria. The study utilized the cross-sectional survey. A total of 50 managers were selected for the study using convenience sampling. Data was collected through structured questionnaire and the data collected were analyzed using spearman rank order correlation. The result of the study revealed a significant and positive relationship between the dimensions of workers welfare and measures of organizational effectiveness. Based on the findings, the study recommended among other things that adequate welfare packages and policies should be put in place by organizations in order to enjoy continuous effectiveness and therefore enjoy sustainable competitive advantage