However, the effects are unlikely to be permanent, researchers said.
Dr Miriam Weber, a neuropsychologist at the University of Rochester Medical Centre, who led the study, said the findings would strike a chord with millions of women going through the menopause.
Memory difficulties are one of the most common symptoms for women in their late 40s and early 50s, she said, a transition stage known as perimenopausal, the 'Daily Mail' reported.
"This study suggests that these problems not only exist but become most evident in the women in the first year following their final menstrual period," she said.
Women develop symptoms such as hot flushes, night sweats, depression, irritability and loss of concentration during menopause.
A study published in the journal Menopause looked at 117 women who were close to the menopause or had just gone through it.
The women were given a series of tests on verbal memory, working memory, attention and information processing.
The tests replicated daily tasks such as staying focused on something for a period of time, learning a phone number, and making a mental list of groceries and recalling them in the supermarket.
The researchers found that women in the early stage of post-menopause performed worse on measures of verbal learning, verbal memory and fine motor skills than women just before going through the menopause or two years into it.
The researchers also found symptoms such as sleep difficulties, depression and anxiety did not predict memory problems.
"While absolute hormone levels could not be linked with cognitive function, it is possible that the fluctuations that occur during this time could play a role in the memory problems that many women experience," Weber said.
Parts of the brain most dependent on oestrogen, which diminishes during the menopause, are important for verbal memory and processing speed, said Weber.
"The most important thing that women need to be reassured of is that these problems, while frustrating, are normal and, in all likelihood, temporary," Weber said.
"When women discover it's probably a symptom of the menopause, they are usually very relieved as they feared they might be suffering from Alzheimer's disease," Dr John Stevenson, of Royal Brompton Hospital in London, said.