Development of the Ta 154 was already well advanced, and the first prototype V1 with Jumo 211F engines. bearing the Stammkennzeichen identification code TE+FE, had its maiden flight on July 1, 1943. It was followed by V2 with Jumo 211N engines, which was kept at the factory for handling trials. V1 was then sent to Rechlin-Lärz airfield for fly-off testing against the He 219A and the new Junckers Ju-388. There the 154 reached almost 700 km/h (440 mph) and easily outflew the other two planes, but those were both fully armed and equipped with radar.

The first armed example of the Ta 154 was the V3 prototype, which also was the first to fit the Jumo 211R engines. The added weight of the guns and drag of the 32-dipole element Matratze radar antennas used on its UHF-band FuG 212 Lichtenstein C-1 radar unit slowed the plane by a full 75 km/h, although it was still somewhat faster than the 219. The rest of the 15 prototypes were then delivered as A-0 models, identical to V3. Some of these also included a raised canopy for better vision to the rear.

It quickly became clear that the Jumo 211R would not be available any time soon, if at all. Future production turned to the more powerful Jumo 213A, but this was also suffering from long delays. The 154 program spent most of the next year testing various prototypes, and sent many of the A-0s to Erprobungskommando 154. During these tests the plane showed an alarming tendency to break its complex lever-action landing gear, and about half of the V series were lost this way.

By June 1944, the Jumo 213 was finally arriving in some numbers, and a production run of 154 A-1s were completed with these engines. Just prior to delivery the only factory making Tego-Film, in Wuppertal, was bombed out by the Royal air Force, and the plywood glue had to be replaced by one that was not as strong, and was later found to react chemically, apparently in a corrosive manner, with the wood in the Ta 154's structure. In July, several A-1s crashed with wing failure due to plywood delamination. This same problem also critically affected the Heinkel He-162 Spatz, Ernst Heinkel's "Volksjäger" jet fighter program entry.

Tank halted production in August, and the RLM eventually cancelled the entire project in September (Milch had been removed by then). At that time about 50 production aircraft had been completed, and a number of the A-0 pre-production planes were later modified to the production standard. Some of the planes served with Nachtjagdgeschwader 3, and a few were later used as training aircraft for jet pilots.

The designation A-2/U3 was given to six A-0s converted into Mistel composite aircraft.

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