The Pilbara Minerals Ltd (ASX: PLS) share price is sliding today.

Shares in the S&P/ASX 200 Index (ASX: XJO) lithium stock closed yesterday trading for $1.37. In morning trade on Thursday, shares are changing hands for $1.35 apiece, down 1.5%.

For some context, the ASX 200 is up 0.2% at this same time.

This underperformance follows the release of Pilbara Minerals' March quarterly results.

Here are the highlights.

Pilbara Minerals share price slips on revenue drop

The Pilbara Minerals share price is slipping after the miner reported spodumene concentrate (lithium) production volume of 125,000 tonnes for the three-month period to 31 March, down 34% from the December quarter.

Management said the slump in lithium production reflected the full quarter impact of the miner's Ngungaju plant being in care and maintenance, tie ins and ramp up of the P1000 Project, and Tropical Cyclone Zelia's impact.

On a brighter note, spodumene prices were up 7% from the December quarter. The ASX 200 lithium stock said its received an average estimated realised price of US$747 per tonne (CIF China) on a ~SC5.3 basis. Sales for the three months came in at 125,500 tonnes.

However, with lower sales volume, the lift in realised prices wasn't enough to boost revenue, which slumped 30% quarter on quarter to $150 million.

Also potentially pressuring the Pilbara Minerals share price today, the miner's unit operating cost (FOB) increased by 10% from the December quarter to $685 per tonne.

Management noted that the cash margin from operations of $39 million reflected the miner's "resilient cash generation from the core business in the current lithium market".

As at 31 March, Pilbara Minerals had a cash balance of $1.1 billion. That was down $109 million from 31 December amid ongoing capital expenditure. But Pilbara Minerals noted it has largely finalised its investment phase and is now focused on optimisation.

The March quarter saw the ASX lithium miner complete its P1000 Project tie ins and ramp up according to plan. First ore was achieved on 31 January, and all performance test criteria were achieved in February.

Management said the Pilgan plant optimisation is targeted for completion in the June quarter. They said, "Pilgan will support higher production volume and lower unit costs through the quarter and throughout FY 2026".

The March quarter also saw Pilbara Minerals complete its acquisition of lithium miner Latin Resources. Pilbara said it has kicked off an exploration program to infill and expand the existing mineral resource. It expects an outcome of ongoing studies next year, in the June quarter of 2026.

Looking ahead, the ASX 200 lithium stock reaffirmed its FY 2025 guidance across all metrics.

With today's intraday dip factored in, the Pilbara Minerals share price is down 39% in 2025.