Investigou-se a presença de assédio moral no trabalho e suas inter-relações com dimensão psicossocial, bem-estar e adaptação psicossocial positiva. As bases teóricas compreenderam: Abordagem Ecológica, Saúde Mental e Trabalho e Psicologia Positiva. No Estudo I, participaram 598 bancários, que responderam questionário biosociodemográfico e laboral, Questionário de Atos Negativos, Job Content Questionnaire, Medidas de Bem-Estar no Trabalho e Escala de Adaptação Psicossocial Positiva. Os dados foram submetidos a estatísticas descritivas, exploratórias e inferenciais. No Estudo II, realizaram-se 4 estudos de casos, e os dados submetidos à análise de conteúdo. Houve alta prevalência de assédio moral e associação com baixo controle, altas demandas, baixo apoio e alta insegurança no emprego. Os níveis de bem-estar no trabalho foram menores para as vítimas. Diferentes fontes de dados (incidência, correlações, preditores e vivências concretas de trabalhadores) indicaram transições ecológicas entre os papéis de vítima, testemunha e agressor e natureza principalmente organizacional do fenômeno.The aim of this study was to investigate workplace bullying and its relations to psychosocial dimension, well-being and positive psychosocial adaptation. Theoretical basis comprehended: Ecological Theory, Work and Mental Health and Positive Psychology. In the first study, 598 banking workers answered demographic and labor questionnaire, Negative Acts Questionnaire, Job Content Questionnaire, Measurements of Well-Being at Work and Positive Psychosocial Adaptation scale. Data were submitted to descriptive, exploratory and inferential statistics. In the second study, 4 multiple case studies were conducted. Data were submitted to qualitative content analysis. The prevalence of workplace bullying was high. It was observed association with low control, high demands, low social support and high job insecurity. The taxes of well-being at work were lower for the victims. Different data resources (incidence, correlations, predictors and concrete experiences of worker) indicate ecological transitions among victims, observers and perpetrators, as well as a mainly organizational nature of workplace bullying.