Background: Obesity has become a leading global public health problem and termed as millennium disease with worldwide spread. Obesity may be a modifiable risk factor for older adult impairment which needs to be completely addressed Aimed to: assess obesity and the functional impairment of older women. Design: Case control design was used. Setting: The present study was done at Kafar Mosa Amran, Zagazig District, Sharkia Governorate. Subjects and methods: 150 older women were selected for the study (75 older women case, 75 older women control) by multistage cluster sampling technique. Tools of data collection: Three categories of tools: the first tool for measuring socio demographic data, BMI, health characteristics of older women, practicing exercises and perception of physical fitness, the second tool was functional impairment questionnaire; the third tool was Lawton instrumental activities of daily livings to assess dependency of older women. Results: 98.7% of study group compare to 64.0% in the control group were impaired and unable to function with statistically significance(X2=29.68 and P=<0.001). 13.5% of the study groups were independent in activities of daily living compared to 42.7% in the control group. Additionally, the study revealed that age and BMI were risk factors for functional impairment. Conclusions: Obesity in women aged 65 or older is associated with greater risk of impaired physical function with greater dependency level on others. Recommendation: Health education campaigns appear to be the most effective interventions to increase awareness of older women concerning obesity related health risks. Experimental study is suggested to manage obesity burden, and the study can also be replicated in urban areas or on larger samples.