Introduction. Lesbian and bisexual (LB) women have higher body weight than heterosexual women. Interventions focused on health and well-being versus weight loss may be more likely to succeed among LB women. This article describes effects of Women's Health and Mindfulness, a 12-week pilot intervention addressing mindfulness, healthy eating, and physical activity, on outcomes associated with chronic disease risk among overweight and obese LB women older than 40 years. Method. Eighty women were randomized, using a stepped-wedge design, to either an immediate- or a delayed-start intervention group; the delayed-start group served as the control. Eligible participants were aged 40 years or older, identified as LB, and had a body mass index of 27 or greater. We compared differences in biological markers of chronic disease, mindfulness, nutrition, and physical activity between immediate- and delayed-start intervention groups. Results. We observed clinically significant improvements in low-density lipoprotein cholesterol but no change in hemoglobin A1c. We found evidence of intervention effects on improved mindfulness and mindful eating scores and on nutrition (improved vegetable intake). Conclusions. The Women's Health and Mindfulness pilot intervention appears to have initiated positive behavioral and physical health changes in this population. Refinements to the intervention model, such as extended intervention duration, and longer term follow-up are warranted to determine sustained effects.