The ThinkPad A series (starting with A20m and A20p) was released as part of IBM's initiative in 2000 to revamp and streamline their lineup of laptops, following decreasing sales.

[3] This included an increasing focus on wireless connectivity, leading to the addition of optional wireless LAN and the option of Bluetooth[4] connecting through the UltraPort,[5] along with promoting internet usage, by offering online demonstrations, tips, and forums to provide user help and share experiences.

Meaning that instead of having a number in front to denote what series of ThinkPad a specific model belongs to, a letter was used instead.

Being described as "a stellar choice for small or large businesses" that "trades portability for power"[7] by CNET in 2002 while reviewing the A3x series.

It offered little compromise when compared to the T series both in the case construction, boasting titanium composite lids,[a] and in the keyboard, offering sturdy and responsive keyboards with 2.7mm of travel,[2] being rated as "a cut above anything you'll find elsewhere, except on some Dell notebooks" by CNET in the same review.

It also had both larger and high resolution IPS screens, a second UltraBay, and web navigation keys on the left of the keyboard,[8] features that no other ThinkPad at the time had.

A carbon fiber case similar to the one in the ThinkPad 240 and 600 series was used to maintain stiffness while keeping the laptop somewhat light.

[9] It had features cut out, including the ability to dock to the full sized ThinkPad Dock,[10] was made of ABS plastic, had a lower end 440MX chipset that couldn't handle as much RAM, did not have battery terminals nor the ability to hot or warm swap in the UltraBay, and couldn't support more than one PCMCIA card.

The other was a smaller model released in March 2001 and didn't have a 1.44MB floppy drive or upgradeable CPUs.

PCWorld gave the A21p a score of 89,[16] rating it the best "Power Notebook" due to its chart topping performance.

In the main review of the laptop, they noted its high resolution screen and high-speed mobile Pentium III processor, calling it the "Lexus of portables".

It was given the Editor's Choice Award from ZDNet in 2001 and was the best rated out of the 7 other "AV notebooks" reviewed, being fast with excellent build quality.

[20] The smaller 14" body type from the mainstream Axxm linup of desktop replacements would be succeeded by the R series.

In a review in 2001, Bloomberg called it the Lexus among portables due to it "[teaming] great design with top-shelf components, as well as a screen resolution of 1600 by 1200, the highest available for notebooks".

[2] It, along with the ThinkPad R30 released at the same time, started the era of ThinkPad design of a cut corner on the left side back side with thin, exposed metal hinges, along with the introduction of page left and right keys which, along with the function row keys were colored in grey.

It also included six web navigation keys on the left side of the keyboard, three of which were preprogramed while the other three were user programmable.

It was described as having a "knockout feature set" and being a "good choice for users who want a bit of portability without breaking the bank" by PCMag in a 2002 review.

Continuing to use IPS display technology, the A31p's screen was described to "remain crisp even to viewers sitting at extreme angles.