Boys are lagging behind their female classmates in the three Rs by the time they are five, new figures show.
It suggests that girls are still ahead in key "early learning" areas, such as writing their own name, reading simple sentences and counting to 20.
More than a third of young boys are not reaching the expected level in writing, while around three in 10 are struggling with their reading and just over one in four have trouble with numbers.
The data, published by the Department for Education (DfE), which shows how well young children are doing in literacy and numeracy, as well as other areas such as physical development, learning to manage feelings and play with others, does reveal that while girls are still outperforming boys, the gap is narrowing in many areas.
Overall, the latest data shows a six percentage point increase in the number of young children who are starting infants school ready to learn, with 66.3% considered to be making a good level of development across the Early Years Foundation Stage (EYFS).
This means that around an extra 38,600 children are reaching the levels expected of them at age five, according to the DfE.
Education Minister Sam Gyimah said it was "great news" that more youngsters are achieving the expected level of development in the early years.
An analysis of the figures shows that that 63.6% of boys reached at least the expected level in writing, compared to 78.3% of girls - a gap of 14.7 percentage points, the largest gulf between the sexes.
It means that around 122,060 young boys could not write simple sentences that could be read by others, with some words spelt correctly.
Boys did better in reading, with 70.6% getting to at least the expected level, meaning they were able to decode regular words and read them aloud, as well being able to read some common irregular words and show they understood what they had read.
But girls again did better, with 81.9 reaching this level, leaving a gap of 11.3 percentage points.
In the area of numbers, 73.6% of boys reached at least the expected level of development, meaning that around 88,760 were struggling to count from one to 20, place numbers in order or do simple adding and subtracting. In comparison, 81.4% of girls achieved the expected level.
And in the area of shape, space and measures, 77.2% of boys reached the expected level, against 84.7% of girls. Youngsters meeting this level are able to talk about and solve simple problems with shapes, measurements, time and money.
Overall, the gender gap has narrowed in the last two years in reading and writing as well as other areas such as managing feelings and behaviour and health and self-care, government statisticians said, but it has been increasing for numbers, shape, the world and technology.
Mr Gyimah, said: "We know that the first few years of a child's life are vital in terms of how well they go on to do at school and beyond.
"It is great news that more children than ever before are achieving the expected level of development in the early years, because parents should be confident that while their children are out of their care, they're not only happy and having fun, but at the same time developing important skills - building confidence with numbers and letters - to ensure they fulfil their potential."