With increasing retirement ages, older workers are working longer while being newly diagnosed with chronic health conditions (CHCs). Our knowledge on how newly diagnosed CHCs influence older workers' vitality and worries is limited. We examine how four newly diagnosed CHCs affect older workers' vitality and worries about physical and mental functional ability. We used data from a Dutch pension panel survey. A sample of 1,894 older workers (60-62 years) was analyzed using conditional change OLS regression models. Having CHCs decreased vitality and increased worries. This effect was worse for older workers newly diagnosed with CHCs. Being newly diagnosed with physically disabling conditions increased worries about physical functioning, while being newly diagnosed with mentally disabling conditions increased worries about mental functioning. These findings aid the identification of vulnerable groups of older workers, thereby informing interventions that could improve quality of life, while promoting healthy aging at work.